diff options
Diffstat (limited to 'security')
53 files changed, 3913 insertions, 528 deletions
diff --git a/security/Kconfig b/security/Kconfig index 7561f6f99f1d..0ced7fd33e4d 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -238,6 +238,7 @@ source "security/loadpin/Kconfig" source "security/yama/Kconfig" source "security/safesetid/Kconfig" source "security/lockdown/Kconfig" +source "security/landlock/Kconfig" source "security/integrity/Kconfig" @@ -277,11 +278,11 @@ endchoice config LSM string "Ordered list of enabled LSMs" - default "lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK - default "lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR - default "lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO - default "lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC - default "lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" + default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK + default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR + default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO + default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC + default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" help A comma-separated list of LSMs, in initialization order. Any LSMs left off this list will be ignored. This can be diff --git a/security/Makefile b/security/Makefile index 3baf435de541..47e432900e24 100644 --- a/security/Makefile +++ b/security/Makefile @@ -13,6 +13,7 @@ subdir-$(CONFIG_SECURITY_LOADPIN) += loadpin subdir-$(CONFIG_SECURITY_SAFESETID) += safesetid subdir-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown subdir-$(CONFIG_BPF_LSM) += bpf +subdir-$(CONFIG_SECURITY_LANDLOCK) += landlock # always enable default capabilities obj-y += commoncap.o @@ -32,6 +33,7 @@ obj-$(CONFIG_SECURITY_SAFESETID) += safesetid/ obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/ obj-$(CONFIG_CGROUPS) += device_cgroup.o obj-$(CONFIG_BPF_LSM) += bpf/ +obj-$(CONFIG_SECURITY_LANDLOCK) += landlock/ # Object integrity file lists subdir-$(CONFIG_INTEGRITY) += integrity diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 240a53387e6b..f72406fe1bf2 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1252,7 +1252,8 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_free, apparmor_task_free), LSM_HOOK_INIT(task_alloc, apparmor_task_alloc), - LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid), + LSM_HOOK_INIT(task_getsecid_subj, apparmor_task_getsecid), + LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid), LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit), LSM_HOOK_INIT(task_kill, apparmor_task_kill), diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index e0828ee7a345..aa6fcfde3051 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -370,7 +370,7 @@ audit: * Returns: 0 on success else error */ static int match_mnt(struct aa_profile *profile, const struct path *path, - char *buffer, struct path *devpath, char *devbuffer, + char *buffer, const struct path *devpath, char *devbuffer, const char *type, unsigned long flags, void *data, bool binary) { @@ -579,7 +579,7 @@ out: return error; } -static int profile_umount(struct aa_profile *profile, struct path *path, +static int profile_umount(struct aa_profile *profile, const struct path *path, char *buffer) { struct aa_perms perms = { }; diff --git a/security/commoncap.c b/security/commoncap.c index 1c519c875217..3f810d37b71b 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -50,7 +50,7 @@ static void warn_setuid_and_fcaps_mixed(const char *fname) /** * cap_capable - Determine whether a task has a particular effective capability * @cred: The credentials to use - * @ns: The user namespace in which we need the capability + * @targ_ns: The user namespace in which we need the capability * @cap: The capability to check for * @opts: Bitmask of options defined in include/linux/security.h * @@ -289,7 +289,7 @@ int cap_capset(struct cred *new, * affects the security markings on that inode, and if it is, should * inode_killpriv() be invoked or the change rejected. * - * Returns 1 if security.capability has a value, meaning inode_killpriv() + * Return: 1 if security.capability has a value, meaning inode_killpriv() * is required, 0 otherwise, meaning inode_killpriv() is not required. */ int cap_inode_need_killpriv(struct dentry *dentry) @@ -315,7 +315,7 @@ int cap_inode_need_killpriv(struct dentry *dentry) * permissions. On non-idmapped mounts or if permission checking is to be * performed on the raw inode simply passs init_user_ns. * - * Returns 0 if successful, -ve on error. + * Return: 0 if successful, -ve on error. */ int cap_inode_killpriv(struct user_namespace *mnt_userns, struct dentry *dentry) { @@ -400,7 +400,7 @@ int cap_inode_getsecurity(struct user_namespace *mnt_userns, &tmpbuf, size, GFP_NOFS); dput(dentry); - if (ret < 0) + if (ret < 0 || !tmpbuf) return ret; fs_ns = inode->i_sb->s_user_ns; @@ -532,7 +532,7 @@ static bool validheader(size_t size, const struct vfs_cap_data *cap) * permissions. On non-idmapped mounts or if permission checking is to be * performed on the raw inode simply passs init_user_ns. * - * If all is ok, we return the new size, on error return < 0. + * Return: On success, return the new size; on error, return < 0. */ int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry, const void **ivalue, size_t size) @@ -881,7 +881,9 @@ static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old, * * Set up the proposed credentials for a new execution context being * constructed by execve(). The proposed creds in @bprm->cred is altered, - * which won't take effect immediately. Returns 0 if successful, -ve on error. + * which won't take effect immediately. + * + * Return: 0 if successful, -ve on error. */ int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) { @@ -1117,7 +1119,9 @@ static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) * @flags: Indications of what has changed * * Fix up the results of setuid() call before the credential changes are - * actually applied, returning 0 to grant the changes, -ve to deny them. + * actually applied. + * + * Return: 0 to grant the changes, -ve to deny them. */ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { @@ -1187,7 +1191,9 @@ static int cap_safe_nice(struct task_struct *p) * @p: The task to affect * * Detemine if the requested scheduler policy change is permitted for the - * specified task, returning 0 if permission is granted, -ve if denied. + * specified task. + * + * Return: 0 if permission is granted, -ve if denied. */ int cap_task_setscheduler(struct task_struct *p) { @@ -1195,12 +1201,14 @@ int cap_task_setscheduler(struct task_struct *p) } /** - * cap_task_ioprio - Detemine if I/O priority change is permitted + * cap_task_setioprio - Detemine if I/O priority change is permitted * @p: The task to affect * @ioprio: The I/O priority to set * * Detemine if the requested I/O priority change is permitted for the specified - * task, returning 0 if permission is granted, -ve if denied. + * task. + * + * Return: 0 if permission is granted, -ve if denied. */ int cap_task_setioprio(struct task_struct *p, int ioprio) { @@ -1208,12 +1216,14 @@ int cap_task_setioprio(struct task_struct *p, int ioprio) } /** - * cap_task_ioprio - Detemine if task priority change is permitted + * cap_task_setnice - Detemine if task priority change is permitted * @p: The task to affect * @nice: The nice value to set * * Detemine if the requested task priority change is permitted for the - * specified task, returning 0 if permission is granted, -ve if denied. + * specified task. + * + * Return: 0 if permission is granted, -ve if denied. */ int cap_task_setnice(struct task_struct *p, int nice) { @@ -1243,12 +1253,15 @@ static int cap_prctl_drop(unsigned long cap) /** * cap_task_prctl - Implement process control functions for this security module * @option: The process control function requested - * @arg2, @arg3, @arg4, @arg5: The argument data for this function + * @arg2: The argument data for this function + * @arg3: The argument data for this function + * @arg4: The argument data for this function + * @arg5: The argument data for this function * * Allow process control functions (sys_prctl()) to alter capabilities; may * also deny access to other functions not otherwise implemented here. * - * Returns 0 or +ve on success, -ENOSYS if this function is not implemented + * Return: 0 or +ve on success, -ENOSYS if this function is not implemented * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM * modules will consider performing the function. */ @@ -1383,7 +1396,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * @pages: The size of the mapping * * Determine whether the allocation of a new virtual mapping by the current - * task is permitted, returning 1 if permission is granted, 0 if not. + * task is permitted. + * + * Return: 1 if permission is granted, 0 if not. */ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { @@ -1396,14 +1411,15 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) return cap_sys_admin; } -/* +/** * cap_mmap_addr - check if able to map given addr * @addr: address attempting to be mapped * * If the process is attempting to map memory below dac_mmap_min_addr they need * CAP_SYS_RAWIO. The other parameters to this function are unused by the - * capability security module. Returns 0 if this mapping should be allowed - * -EPERM if not. + * capability security module. + * + * Return: 0 if this mapping should be allowed or -EPERM if not. */ int cap_mmap_addr(unsigned long addr) { diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 250fb0836156..3b06a01bd0fd 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -111,6 +111,8 @@ static int __init __integrity_init_keyring(const unsigned int id, } else { if (id == INTEGRITY_KEYRING_PLATFORM) set_platform_trusted_keys(keyring[id]); + if (id == INTEGRITY_KEYRING_IMA) + load_module_cert(keyring[id]); } return err; diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c index a662024b4c70..23240d793b07 100644 --- a/security/integrity/digsig_asymmetric.c +++ b/security/integrity/digsig_asymmetric.c @@ -84,6 +84,7 @@ int asymmetric_verify(struct key *keyring, const char *sig, { struct public_key_signature pks; struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig; + const struct public_key *pk; struct key *key; int ret; @@ -105,23 +106,20 @@ int asymmetric_verify(struct key *keyring, const char *sig, memset(&pks, 0, sizeof(pks)); pks.hash_algo = hash_algo_name[hdr->hash_algo]; - switch (hdr->hash_algo) { - case HASH_ALGO_STREEBOG_256: - case HASH_ALGO_STREEBOG_512: - /* EC-RDSA and Streebog should go together. */ - pks.pkey_algo = "ecrdsa"; - pks.encoding = "raw"; - break; - case HASH_ALGO_SM3_256: - /* SM2 and SM3 should go together. */ - pks.pkey_algo = "sm2"; - pks.encoding = "raw"; - break; - default: - pks.pkey_algo = "rsa"; + + pk = asymmetric_key_public_key(key); + pks.pkey_algo = pk->pkey_algo; + if (!strcmp(pk->pkey_algo, "rsa")) pks.encoding = "pkcs1"; - break; - } + else if (!strncmp(pk->pkey_algo, "ecdsa-", 6)) + /* edcsa-nist-p192 etc. */ + pks.encoding = "x962"; + else if (!strcmp(pk->pkey_algo, "ecrdsa") || + !strcmp(pk->pkey_algo, "sm2")) + pks.encoding = "raw"; + else + return -ENOPKG; + pks.digest = (u8 *)data; pks.digest_size = datalen; pks.s = hdr->sig; diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 0ba01847e836..fca8a9409e4a 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -160,7 +160,7 @@ void integrity_inode_free(struct inode *inode) static void init_once(void *foo) { - struct integrity_iint_cache *iint = foo; + struct integrity_iint_cache *iint = (struct integrity_iint_cache *) foo; memset(iint, 0, sizeof(*iint)); iint->ima_file_status = INTEGRITY_UNKNOWN; diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 8e8b5251550e..f0e448ed1f9f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -24,10 +24,6 @@ #include "../integrity.h" -#ifdef CONFIG_HAVE_IMA_KEXEC -#include <asm/ima.h> -#endif - enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 }; diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 565e33ff19d0..4e5eb0236278 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -76,7 +76,7 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode, if (!ima_appraise) return 0; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); return ima_match_policy(mnt_userns, inode, current_cred(), secid, func, mask, IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL); } diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index e29bea3dd4cc..667887665823 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -10,6 +10,7 @@ #include <linux/seq_file.h> #include <linux/vmalloc.h> #include <linux/kexec.h> +#include <linux/of.h> #include "ima.h" #ifdef CONFIG_IMA_KEXEC @@ -123,12 +124,8 @@ void ima_add_kexec_buffer(struct kimage *image) return; } - ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size); - if (ret) { - pr_err("Error passing over kexec measurement buffer.\n"); - return; - } - + image->ima_buffer_addr = kbuf.mem; + image->ima_buffer_size = kexec_segment_size; image->ima_buffer = kexec_buffer; pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 9ef748ea829f..906c1d8e0b71 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -391,7 +391,7 @@ int ima_file_mmap(struct file *file, unsigned long prot) u32 secid; if (file && (prot & PROT_EXEC)) { - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); return process_measurement(file, current_cred(), secid, NULL, 0, MAY_EXEC, MMAP_CHECK); } @@ -429,7 +429,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC)) return 0; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); inode = file_inode(vma->vm_file); action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode, current_cred(), secid, MAY_EXEC, MMAP_CHECK, @@ -470,7 +470,7 @@ int ima_bprm_check(struct linux_binprm *bprm) int ret; u32 secid; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, MAY_EXEC, BPRM_CHECK); if (ret) @@ -482,7 +482,7 @@ int ima_bprm_check(struct linux_binprm *bprm) } /** - * ima_path_check - based on policy, collect/store measurement. + * ima_file_check - based on policy, collect/store measurement. * @file: pointer to the file to be measured * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND * @@ -495,7 +495,7 @@ int ima_file_check(struct file *file, int mask) { u32 secid; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); return process_measurement(file, current_cred(), secid, NULL, 0, mask & (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND), FILE_CHECK); @@ -606,6 +606,9 @@ void ima_post_create_tmpfile(struct user_namespace *mnt_userns, struct integrity_iint_cache *iint; int must_appraise; + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, FILE_CHECK); if (!must_appraise) @@ -636,6 +639,9 @@ void ima_post_path_mknod(struct user_namespace *mnt_userns, struct inode *inode = dentry->d_inode; int must_appraise; + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, FILE_CHECK); if (!must_appraise) @@ -686,7 +692,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, /* Read entire file for all partial reads. */ func = read_idmap[read_id] ?: FILE_CHECK; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); return process_measurement(file, current_cred(), secid, NULL, 0, MAY_READ, func); } @@ -729,7 +735,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, } func = read_idmap[read_id] ?: FILE_CHECK; - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); return process_measurement(file, current_cred(), secid, buf, size, MAY_READ, func); } @@ -780,6 +786,7 @@ int ima_load_data(enum kernel_load_data_id id, bool contents) pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n"); return -EACCES; /* INTEGRITY_UNKNOWN */ } + break; default: break; } @@ -872,7 +879,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, * buffer measurements. */ if (func) { - security_task_getsecid(current, &secid); + security_task_getsecid_subj(current, &secid); action = ima_get_action(mnt_userns, inode, current_cred(), secid, 0, func, &pcr, &template, func_data); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 4f8cb155e4fd..fd5d46e511f1 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -599,6 +599,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, rc = ima_filter_rule_match(secid, rule->lsm[i].type, Audit_equal, rule->lsm[i].rule); + break; default: break; } @@ -836,6 +837,7 @@ void __init ima_init_policy(void) add_rules(default_measurement_rules, ARRAY_SIZE(default_measurement_rules), IMA_DEFAULT_POLICY); + break; default: break; } diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index e22e510ae92d..4e081e650047 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -494,8 +494,8 @@ int ima_restore_measurement_list(loff_t size, void *buf) } } - entry->pcr = !ima_canonical_fmt ? *(hdr[HDR_PCR].data) : - le32_to_cpu(*(hdr[HDR_PCR].data)); + entry->pcr = !ima_canonical_fmt ? *(u32 *)(hdr[HDR_PCR].data) : + le32_to_cpu(*(u32 *)(hdr[HDR_PCR].data)); ret = ima_restore_measurement_entry(entry); if (ret < 0) break; diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c index c5ba695c10e3..5604bd57c990 100644 --- a/security/integrity/platform_certs/keyring_handler.c +++ b/security/integrity/platform_certs/keyring_handler.c @@ -56,6 +56,15 @@ static __init void uefi_blacklist_binary(const char *source, } /* + * Add an X509 cert to the revocation list. + */ +static __init void uefi_revocation_list_x509(const char *source, + const void *data, size_t len) +{ + add_key_to_revocation_list(data, len); +} + +/* * Return the appropriate handler for particular signature list types found in * the UEFI db and MokListRT tables. */ @@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) return uefi_blacklist_x509_tbs; if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) return uefi_blacklist_binary; + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return uefi_revocation_list_x509; return 0; } diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index ee4b4c666854..f290f78c3f30 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -132,8 +132,9 @@ static int __init load_moklist_certs(void) static int __init load_uefi_certs(void) { efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID; - void *db = NULL, *dbx = NULL; - unsigned long dbsize = 0, dbxsize = 0; + efi_guid_t mok_var = EFI_SHIM_LOCK_GUID; + void *db = NULL, *dbx = NULL, *mokx = NULL; + unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0; efi_status_t status; int rc = 0; @@ -175,6 +176,21 @@ static int __init load_uefi_certs(void) kfree(dbx); } + mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); + if (!mokx) { + if (status == EFI_NOT_FOUND) + pr_debug("mokx variable wasn't found\n"); + else + pr_info("Couldn't get mokx list\n"); + } else { + rc = parse_efi_signature_list("UEFI:MokListXRT", + mokx, mokxsize, + get_handler_for_dbx); + if (rc) + pr_err("Couldn't parse mokx signatures %d\n", rc); + kfree(mokx); + } + /* Load the MokListRT certs */ rc = load_moklist_certs(); diff --git a/security/keys/Kconfig b/security/keys/Kconfig index c161642a8484..64b81abd087e 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -75,6 +75,9 @@ config TRUSTED_KEYS select CRYPTO_HMAC select CRYPTO_SHA1 select CRYPTO_HASH_INFO + select ASN1_ENCODER + select OID_REGISTRY + select ASN1 help This option provides support for creating, sealing, and unsealing keys in the kernel. Trusted keys are random number symmetric keys, diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73cebbb378..feb8b6c3cc79 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,11 @@ # obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_core.o trusted-y += trusted_tpm1.o + +$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h trusted-y += trusted_tpm2.o +trusted-y += tpm2key.asn1.o + +trusted-$(CONFIG_TEE) += trusted_tee.o diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/security/keys/trusted-keys/tpm2key.asn1 new file mode 100644 index 000000000000..f57f869ad600 --- /dev/null +++ b/security/keys/trusted-keys/tpm2key.asn1 @@ -0,0 +1,11 @@ +--- +--- ASN.1 for TPM 2.0 keys +--- + +TPMKey ::= SEQUENCE { + type OBJECT IDENTIFIER ({tpm2_key_type}), + emptyAuth [0] EXPLICIT BOOLEAN OPTIONAL, + parent INTEGER ({tpm2_key_parent}), + pubkey OCTET STRING ({tpm2_key_pub}), + privkey OCTET STRING ({tpm2_key_priv}) + } diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c new file mode 100644 index 000000000000..d5c891d8d353 --- /dev/null +++ b/security/keys/trusted-keys/trusted_core.c @@ -0,0 +1,360 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (c) 2019-2021, Linaro Limited + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <keys/trusted_tee.h> +#include <keys/trusted_tpm.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/static_call.h> +#include <linux/string.h> +#include <linux/uaccess.h> + +static char *trusted_key_source; +module_param_named(source, trusted_key_source, charp, 0); +MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); + +static const struct trusted_key_source trusted_key_sources[] = { +#if defined(CONFIG_TCG_TPM) + { "tpm", &trusted_key_tpm_ops }, +#endif +#if defined(CONFIG_TEE) + { "tee", &trusted_key_tee_ops }, +#endif +}; + +DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init); +DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal); +DEFINE_STATIC_CALL_NULL(trusted_key_unseal, + *trusted_key_sources[0].ops->unseal); +DEFINE_STATIC_CALL_NULL(trusted_key_get_random, + *trusted_key_sources[0].ops->get_random); +DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit); +static unsigned char migratable; + +enum { + Opt_err, + Opt_new, Opt_load, Opt_update, +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +/* + * datablob_parse - parse the keyctl data and fill in the + * payload structure + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char **datablob, struct trusted_key_payload *p) +{ + substring_t args[MAX_OPT_ARGS]; + long keylen; + int ret = -EINVAL; + int key_cmd; + char *c; + + /* main command */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + key_cmd = match_token(c, key_tokens, args); + switch (key_cmd) { + case Opt_new: + /* first argument is key size */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + ret = kstrtol(c, 10, &keylen); + if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) + return -EINVAL; + p->key_len = keylen; + ret = Opt_new; + break; + case Opt_load: + /* first argument is sealed blob */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + p->blob_len = strlen(c) / 2; + if (p->blob_len > MAX_BLOB_SIZE) + return -EINVAL; + ret = hex2bin(p->blob, c, p->blob_len); + if (ret < 0) + return -EINVAL; + ret = Opt_load; + break; + case Opt_update: + ret = Opt_update; + break; + case Opt_err: + return -EINVAL; + } + return ret; +} + +static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{ + struct trusted_key_payload *p = NULL; + int ret; + + ret = key_payload_reserve(key, sizeof(*p)); + if (ret < 0) + goto err; + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + goto err; + + p->migratable = migratable; +err: + return p; +} + +/* + * trusted_instantiate - create a new trusted key + * + * Unseal an existing trusted blob or, for a new key, get a + * random key, then seal and create a trusted key-type key, + * adding it to the specified keyring. + * + * On success, return 0. Otherwise return errno. + */ +static int trusted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *payload = NULL; + size_t datalen = prep->datalen; + char *datablob, *orig_datablob; + int ret = 0; + int key_cmd; + size_t key_len; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + + payload = trusted_payload_alloc(key); + if (!payload) { + ret = -ENOMEM; + goto out; + } + + key_cmd = datablob_parse(&datablob, payload); + if (key_cmd < 0) { + ret = key_cmd; + goto out; + } + + dump_payload(payload); + + switch (key_cmd) { + case Opt_load: + ret = static_call(trusted_key_unseal)(payload, datablob); + dump_payload(payload); + if (ret < 0) + pr_info("key_unseal failed (%d)\n", ret); + break; + case Opt_new: + key_len = payload->key_len; + ret = static_call(trusted_key_get_random)(payload->key, + key_len); + if (ret < 0) + goto out; + + if (ret != key_len) { + pr_info("key_create failed (%d)\n", ret); + ret = -EIO; + goto out; + } + + ret = static_call(trusted_key_seal)(payload, datablob); + if (ret < 0) + pr_info("key_seal failed (%d)\n", ret); + break; + default: + ret = -EINVAL; + } +out: + kfree_sensitive(orig_datablob); + if (!ret) + rcu_assign_keypointer(key, payload); + else + kfree_sensitive(payload); + return ret; +} + +static void trusted_rcu_free(struct rcu_head *rcu) +{ + struct trusted_key_payload *p; + + p = container_of(rcu, struct trusted_key_payload, rcu); + kfree_sensitive(p); +} + +/* + * trusted_update - reseal an existing key with new PCR values + */ +static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *p; + struct trusted_key_payload *new_p; + size_t datalen = prep->datalen; + char *datablob, *orig_datablob; + int ret = 0; + + if (key_is_negative(key)) + return -ENOKEY; + p = key->payload.data[0]; + if (!p->migratable) + return -EPERM; + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + + new_p = trusted_payload_alloc(key); + if (!new_p) { + ret = -ENOMEM; + goto out; + } + + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + ret = datablob_parse(&datablob, new_p); + if (ret != Opt_update) { + ret = -EINVAL; + kfree_sensitive(new_p); + goto out; + } + + /* copy old key values, and reseal with new pcrs */ + new_p->migratable = p->migratable; + new_p->key_len = p->key_len; + memcpy(new_p->key, p->key, p->key_len); + dump_payload(p); + dump_payload(new_p); + + ret = static_call(trusted_key_seal)(new_p, datablob); + if (ret < 0) { + pr_info("key_seal failed (%d)\n", ret); + kfree_sensitive(new_p); + goto out; + } + + rcu_assign_keypointer(key, new_p); + call_rcu(&p->rcu, trusted_rcu_free); +out: + kfree_sensitive(orig_datablob); + return ret; +} + +/* + * trusted_read - copy the sealed blob data to userspace in hex. + * On success, return to userspace the trusted key datablob size. + */ +static long trusted_read(const struct key *key, char *buffer, + size_t buflen) +{ + const struct trusted_key_payload *p; + char *bufp; + int i; + + p = dereference_key_locked(key); + if (!p) + return -EINVAL; + + if (buffer && buflen >= 2 * p->blob_len) { + bufp = buffer; + for (i = 0; i < p->blob_len; i++) + bufp = hex_byte_pack(bufp, p->blob[i]); + } + return 2 * p->blob_len; +} + +/* + * trusted_destroy - clear and free the key's payload + */ +static void trusted_destroy(struct key *key) +{ + kfree_sensitive(key->payload.data[0]); +} + +struct key_type key_type_trusted = { + .name = "trusted", + .instantiate = trusted_instantiate, + .update = trusted_update, + .destroy = trusted_destroy, + .describe = user_describe, + .read = trusted_read, +}; +EXPORT_SYMBOL_GPL(key_type_trusted); + +static int __init init_trusted(void) +{ + int i, ret = 0; + + for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) { + if (trusted_key_source && + strncmp(trusted_key_source, trusted_key_sources[i].name, + strlen(trusted_key_sources[i].name))) + continue; + + static_call_update(trusted_key_init, + trusted_key_sources[i].ops->init); + static_call_update(trusted_key_seal, + trusted_key_sources[i].ops->seal); + static_call_update(trusted_key_unseal, + trusted_key_sources[i].ops->unseal); + static_call_update(trusted_key_get_random, + trusted_key_sources[i].ops->get_random); + static_call_update(trusted_key_exit, + trusted_key_sources[i].ops->exit); + migratable = trusted_key_sources[i].ops->migratable; + + ret = static_call(trusted_key_init)(); + if (!ret) + break; + } + + /* + * encrypted_keys.ko depends on successful load of this module even if + * trusted key implementation is not found. + */ + if (ret == -ENODEV) + return 0; + + return ret; +} + +static void __exit cleanup_trusted(void) +{ + static_call(trusted_key_exit)(); +} + +late_initcall(init_trusted); +module_exit(cleanup_trusted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c new file mode 100644 index 000000000000..2ce66c199e1d --- /dev/null +++ b/security/keys/trusted-keys/trusted_tee.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019-2021 Linaro Ltd. + * + * Author: + * Sumit Garg <sumit.garg@linaro.org> + */ + +#include <linux/err.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/tee_drv.h> +#include <linux/uuid.h> + +#include <keys/trusted_tee.h> + +#define DRIVER_NAME "trusted-key-tee" + +/* + * Get random data for symmetric key + * + * [out] memref[0] Random data + */ +#define TA_CMD_GET_RANDOM 0x0 + +/* + * Seal trusted key using hardware unique key + * + * [in] memref[0] Plain key + * [out] memref[1] Sealed key datablob + */ +#define TA_CMD_SEAL 0x1 + +/* + * Unseal trusted key using hardware unique key + * + * [in] memref[0] Sealed key datablob + * [out] memref[1] Plain key + */ +#define TA_CMD_UNSEAL 0x2 + +/** + * struct trusted_key_tee_private - TEE Trusted key private data + * @dev: TEE based Trusted key device. + * @ctx: TEE context handler. + * @session_id: Trusted key TA session identifier. + * @shm_pool: Memory pool shared with TEE device. + */ +struct trusted_key_tee_private { + struct device *dev; + struct tee_context *ctx; + u32 session_id; + struct tee_shm *shm_pool; +}; + +static struct trusted_key_tee_private pvt_data; + +/* + * Have the TEE seal(encrypt) the symmetric key + */ +static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm_in = tee_shm_register(pvt_data.ctx, (unsigned long)p->key, + p->key_len, TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_in)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + return PTR_ERR(reg_shm_in); + } + + reg_shm_out = tee_shm_register(pvt_data.ctx, (unsigned long)p->blob, + sizeof(p->blob), TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_out)) { + dev_err(pvt_data.dev, "blob shm register failed\n"); + ret = PTR_ERR(reg_shm_out); + goto out; + } + + inv_arg.func = TA_CMD_SEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm_in; + param[0].u.memref.size = p->key_len; + param[0].u.memref.shm_offs = 0; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm_out; + param[1].u.memref.size = sizeof(p->blob); + param[1].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->blob_len = param[1].u.memref.size; + } + +out: + if (reg_shm_out) + tee_shm_free(reg_shm_out); + if (reg_shm_in) + tee_shm_free(reg_shm_in); + + return ret; +} + +/* + * Have the TEE unseal(decrypt) the symmetric key + */ +static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm_in = tee_shm_register(pvt_data.ctx, (unsigned long)p->blob, + p->blob_len, TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_in)) { + dev_err(pvt_data.dev, "blob shm register failed\n"); + return PTR_ERR(reg_shm_in); + } + + reg_shm_out = tee_shm_register(pvt_data.ctx, (unsigned long)p->key, + sizeof(p->key), TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_out)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + ret = PTR_ERR(reg_shm_out); + goto out; + } + + inv_arg.func = TA_CMD_UNSEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm_in; + param[0].u.memref.size = p->blob_len; + param[0].u.memref.shm_offs = 0; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm_out; + param[1].u.memref.size = sizeof(p->key); + param[1].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->key_len = param[1].u.memref.size; + } + +out: + if (reg_shm_out) + tee_shm_free(reg_shm_out); + if (reg_shm_in) + tee_shm_free(reg_shm_in); + + return ret; +} + +/* + * Have the TEE generate random symmetric key + */ +static int trusted_tee_get_random(unsigned char *key, size_t key_len) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm = tee_shm_register(pvt_data.ctx, (unsigned long)key, key_len, + TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + return PTR_ERR(reg_shm); + } + + inv_arg.func = TA_CMD_GET_RANDOM; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[0].u.memref.shm = reg_shm; + param[0].u.memref.size = key_len; + param[0].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + ret = param[0].u.memref.size; + } + + tee_shm_free(reg_shm); + + return ret; +} + +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + if (ver->impl_id == TEE_IMPL_ID_OPTEE) + return 1; + else + return 0; +} + +static int trusted_key_probe(struct device *dev) +{ + struct tee_client_device *rng_device = to_tee_client_device(dev); + int ret; + struct tee_ioctl_open_session_arg sess_arg; + + memset(&sess_arg, 0, sizeof(sess_arg)); + + pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, + NULL); + if (IS_ERR(pvt_data.ctx)) + return -ENODEV; + + memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + sess_arg.num_params = 0; + + ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL); + if ((ret < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "tee_client_open_session failed, err: %x\n", + sess_arg.ret); + ret = -EINVAL; + goto out_ctx; + } + pvt_data.session_id = sess_arg.session; + + ret = register_key_type(&key_type_trusted); + if (ret < 0) + goto out_sess; + + pvt_data.dev = dev; + + return 0; + +out_sess: + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); +out_ctx: + tee_client_close_context(pvt_data.ctx); + + return ret; +} + +static int trusted_key_remove(struct device *dev) +{ + unregister_key_type(&key_type_trusted); + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); + tee_client_close_context(pvt_data.ctx); + + return 0; +} + +static const struct tee_client_device_id trusted_key_id_table[] = { + {UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b, + 0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)}, + {} +}; +MODULE_DEVICE_TABLE(tee, trusted_key_id_table); + +static struct tee_client_driver trusted_key_driver = { + .id_table = trusted_key_id_table, + .driver = { + .name = DRIVER_NAME, + .bus = &tee_bus_type, + .probe = trusted_key_probe, + .remove = trusted_key_remove, + }, +}; + +static int trusted_tee_init(void) +{ + return driver_register(&trusted_key_driver.driver); +} + +static void trusted_tee_exit(void) +{ + driver_unregister(&trusted_key_driver.driver); +} + +struct trusted_key_ops trusted_key_tee_ops = { + .migratable = 0, /* non-migratable */ + .init = trusted_tee_init, + .seal = trusted_tee_seal, + .unseal = trusted_tee_unseal, + .get_random = trusted_tee_get_random, + .exit = trusted_tee_exit, +}; diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 493eb91ed017..469394550801 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1,29 +1,22 @@ // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2010 IBM Corporation - * - * Author: - * David Safford <safford@us.ibm.com> + * Copyright (c) 2019-2021, Linaro Limited * * See Documentation/security/keys/trusted-encrypted.rst */ #include <crypto/hash_info.h> -#include <linux/uaccess.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/parser.h> #include <linux/string.h> #include <linux/err.h> -#include <keys/user-type.h> #include <keys/trusted-type.h> #include <linux/key-type.h> -#include <linux/rcupdate.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha1.h> -#include <linux/capability.h> #include <linux/tpm.h> #include <linux/tpm_command.h> @@ -63,7 +56,7 @@ static int TSS_sha1(const unsigned char *data, unsigned int datalen, sdesc = init_sdesc(hashalg); if (IS_ERR(sdesc)) { - pr_info("trusted_key: can't alloc %s\n", hash_alg); + pr_info("can't alloc %s\n", hash_alg); return PTR_ERR(sdesc); } @@ -83,7 +76,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, sdesc = init_sdesc(hmacalg); if (IS_ERR(sdesc)) { - pr_info("trusted_key: can't alloc %s\n", hmac_alg); + pr_info("can't alloc %s\n", hmac_alg); return PTR_ERR(sdesc); } @@ -136,7 +129,7 @@ int TSS_authhmac(unsigned char *digest, const unsigned char *key, sdesc = init_sdesc(hashalg); if (IS_ERR(sdesc)) { - pr_info("trusted_key: can't alloc %s\n", hash_alg); + pr_info("can't alloc %s\n", hash_alg); return PTR_ERR(sdesc); } @@ -212,7 +205,7 @@ int TSS_checkhmac1(unsigned char *buffer, sdesc = init_sdesc(hashalg); if (IS_ERR(sdesc)) { - pr_info("trusted_key: can't alloc %s\n", hash_alg); + pr_info("can't alloc %s\n", hash_alg); return PTR_ERR(sdesc); } ret = crypto_shash_init(&sdesc->shash); @@ -305,7 +298,7 @@ static int TSS_checkhmac2(unsigned char *buffer, sdesc = init_sdesc(hashalg); if (IS_ERR(sdesc)) { - pr_info("trusted_key: can't alloc %s\n", hash_alg); + pr_info("can't alloc %s\n", hash_alg); return PTR_ERR(sdesc); } ret = crypto_shash_init(&sdesc->shash); @@ -597,12 +590,12 @@ static int tpm_unseal(struct tpm_buf *tb, /* sessions for unsealing key and data */ ret = oiap(tb, &authhandle1, enonce1); if (ret < 0) { - pr_info("trusted_key: oiap failed (%d)\n", ret); + pr_info("oiap failed (%d)\n", ret); return ret; } ret = oiap(tb, &authhandle2, enonce2); if (ret < 0) { - pr_info("trusted_key: oiap failed (%d)\n", ret); + pr_info("oiap failed (%d)\n", ret); return ret; } @@ -612,7 +605,7 @@ static int tpm_unseal(struct tpm_buf *tb, return ret; if (ret != TPM_NONCE_SIZE) { - pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); + pr_info("tpm_get_random failed (%d)\n", ret); return -EIO; } ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, @@ -641,7 +634,7 @@ static int tpm_unseal(struct tpm_buf *tb, ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); if (ret < 0) { - pr_info("trusted_key: authhmac failed (%d)\n", ret); + pr_info("authhmac failed (%d)\n", ret); return ret; } @@ -653,7 +646,7 @@ static int tpm_unseal(struct tpm_buf *tb, *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, 0); if (ret < 0) { - pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); + pr_info("TSS_checkhmac2 failed (%d)\n", ret); return ret; } memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); @@ -680,7 +673,7 @@ static int key_seal(struct trusted_key_payload *p, p->key, p->key_len + 1, p->blob, &p->blob_len, o->blobauth, o->pcrinfo, o->pcrinfo_len); if (ret < 0) - pr_info("trusted_key: srkseal failed (%d)\n", ret); + pr_info("srkseal failed (%d)\n", ret); tpm_buf_destroy(&tb); return ret; @@ -702,7 +695,7 @@ static int key_unseal(struct trusted_key_payload *p, ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, o->blobauth, p->key, &p->key_len); if (ret < 0) - pr_info("trusted_key: srkunseal failed (%d)\n", ret); + pr_info("srkunseal failed (%d)\n", ret); else /* pull migratable flag out of sealed key */ p->migratable = p->key[--p->key_len]; @@ -713,7 +706,6 @@ static int key_unseal(struct trusted_key_payload *p, enum { Opt_err, - Opt_new, Opt_load, Opt_update, Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash, @@ -722,9 +714,6 @@ enum { }; static const match_table_t key_tokens = { - {Opt_new, "new"}, - {Opt_load, "load"}, - {Opt_update, "update"}, {Opt_keyhandle, "keyhandle=%s"}, {Opt_keyauth, "keyauth=%s"}, {Opt_blobauth, "blobauth=%s"}, @@ -758,6 +747,9 @@ static int getoptions(char *c, struct trusted_key_payload *pay, opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1; + if (!c) + return 0; + while ((p = strsep(&c, " \t"))) { if (*p == '\0' || *p == ' ' || *p == '\t') continue; @@ -791,13 +783,33 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return -EINVAL; break; case Opt_blobauth: - if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) - return -EINVAL; - res = hex2bin(opt->blobauth, args[0].from, - SHA1_DIGEST_SIZE); - if (res < 0) - return -EINVAL; + /* + * TPM 1.2 authorizations are sha1 hashes passed in as + * hex strings. TPM 2.0 authorizations are simple + * passwords (although it can take a hash as well) + */ + opt->blobauth_len = strlen(args[0].from); + + if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) { + res = hex2bin(opt->blobauth, args[0].from, + TPM_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + + opt->blobauth_len = TPM_DIGEST_SIZE; + break; + } + + if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) { + memcpy(opt->blobauth, args[0].from, + opt->blobauth_len); + break; + } + + return -EINVAL; + break; + case Opt_migratable: if (*args[0].from == '0') pay->migratable = 0; @@ -822,7 +834,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay, if (i == HASH_ALGO__LAST) return -EINVAL; if (!tpm2 && i != HASH_ALGO_SHA1) { - pr_info("trusted_key: TPM 1.x only supports SHA-1.\n"); + pr_info("TPM 1.x only supports SHA-1.\n"); return -EINVAL; } break; @@ -851,71 +863,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return 0; } -/* - * datablob_parse - parse the keyctl data and fill in the - * payload and options structures - * - * On success returns 0, otherwise -EINVAL. - */ -static int datablob_parse(char *datablob, struct trusted_key_payload *p, - struct trusted_key_options *o) -{ - substring_t args[MAX_OPT_ARGS]; - long keylen; - int ret = -EINVAL; - int key_cmd; - char *c; - - /* main command */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - key_cmd = match_token(c, key_tokens, args); - switch (key_cmd) { - case Opt_new: - /* first argument is key size */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - ret = kstrtol(c, 10, &keylen); - if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) - return -EINVAL; - p->key_len = keylen; - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_new; - break; - case Opt_load: - /* first argument is sealed blob */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - p->blob_len = strlen(c) / 2; - if (p->blob_len > MAX_BLOB_SIZE) - return -EINVAL; - ret = hex2bin(p->blob, c, p->blob_len); - if (ret < 0) - return -EINVAL; - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_load; - break; - case Opt_update: - /* all arguments are options */ - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_update; - break; - case Opt_err: - return -EINVAL; - break; - } - return ret; -} - static struct trusted_key_options *trusted_options_alloc(void) { struct trusted_key_options *options; @@ -936,252 +883,99 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; } -static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob) { - struct trusted_key_payload *p = NULL; - int ret; - - ret = key_payload_reserve(key, sizeof *p); - if (ret < 0) - return p; - p = kzalloc(sizeof *p, GFP_KERNEL); - if (p) - p->migratable = 1; /* migratable by default */ - return p; -} - -/* - * trusted_instantiate - create a new trusted key - * - * Unseal an existing trusted blob or, for a new key, get a - * random key, then seal and create a trusted key-type key, - * adding it to the specified keyring. - * - * On success, return 0. Otherwise return errno. - */ -static int trusted_instantiate(struct key *key, - struct key_preparsed_payload *prep) -{ - struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL; - size_t datalen = prep->datalen; - char *datablob; int ret = 0; - int key_cmd; - size_t key_len; int tpm2; tpm2 = tpm_is_tpm2(chip); if (tpm2 < 0) return tpm2; - if (datalen <= 0 || datalen > 32767 || !prep->data) - return -EINVAL; - - datablob = kmalloc(datalen + 1, GFP_KERNEL); - if (!datablob) + options = trusted_options_alloc(); + if (!options) return -ENOMEM; - memcpy(datablob, prep->data, datalen); - datablob[datalen] = '\0'; - options = trusted_options_alloc(); - if (!options) { - ret = -ENOMEM; - goto out; - } - payload = trusted_payload_alloc(key); - if (!payload) { - ret = -ENOMEM; + ret = getoptions(datablob, p, options); + if (ret < 0) goto out; - } + dump_options(options); - key_cmd = datablob_parse(datablob, payload, options); - if (key_cmd < 0) { - ret = key_cmd; + if (!options->keyhandle && !tpm2) { + ret = -EINVAL; goto out; } - if (!options->keyhandle) { - ret = -EINVAL; + if (tpm2) + ret = tpm2_seal_trusted(chip, p, options); + else + ret = key_seal(p, options); + if (ret < 0) { + pr_info("key_seal failed (%d)\n", ret); goto out; } - dump_payload(payload); - dump_options(options); - - switch (key_cmd) { - case Opt_load: - if (tpm2) - ret = tpm2_unseal_trusted(chip, payload, options); - else - ret = key_unseal(payload, options); - dump_payload(payload); - dump_options(options); - if (ret < 0) - pr_info("trusted_key: key_unseal failed (%d)\n", ret); - break; - case Opt_new: - key_len = payload->key_len; - ret = tpm_get_random(chip, payload->key, key_len); - if (ret < 0) - goto out; - - if (ret != key_len) { - pr_info("trusted_key: key_create failed (%d)\n", ret); - ret = -EIO; + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); + if (ret < 0) { + pr_info("pcrlock failed (%d)\n", ret); goto out; } - if (tpm2) - ret = tpm2_seal_trusted(chip, payload, options); - else - ret = key_seal(payload, options); - if (ret < 0) - pr_info("trusted_key: key_seal failed (%d)\n", ret); - break; - default: - ret = -EINVAL; - goto out; } - if (!ret && options->pcrlock) - ret = pcrlock(options->pcrlock); out: - kfree_sensitive(datablob); kfree_sensitive(options); - if (!ret) - rcu_assign_keypointer(key, payload); - else - kfree_sensitive(payload); return ret; } -static void trusted_rcu_free(struct rcu_head *rcu) +static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob) { - struct trusted_key_payload *p; - - p = container_of(rcu, struct trusted_key_payload, rcu); - kfree_sensitive(p); -} - -/* - * trusted_update - reseal an existing key with new PCR values - */ -static int trusted_update(struct key *key, struct key_preparsed_payload *prep) -{ - struct trusted_key_payload *p; - struct trusted_key_payload *new_p; - struct trusted_key_options *new_o; - size_t datalen = prep->datalen; - char *datablob; + struct trusted_key_options *options = NULL; int ret = 0; + int tpm2; - if (key_is_negative(key)) - return -ENOKEY; - p = key->payload.data[0]; - if (!p->migratable) - return -EPERM; - if (datalen <= 0 || datalen > 32767 || !prep->data) - return -EINVAL; + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return tpm2; - datablob = kmalloc(datalen + 1, GFP_KERNEL); - if (!datablob) + options = trusted_options_alloc(); + if (!options) return -ENOMEM; - new_o = trusted_options_alloc(); - if (!new_o) { - ret = -ENOMEM; - goto out; - } - new_p = trusted_payload_alloc(key); - if (!new_p) { - ret = -ENOMEM; - goto out; - } - memcpy(datablob, prep->data, datalen); - datablob[datalen] = '\0'; - ret = datablob_parse(datablob, new_p, new_o); - if (ret != Opt_update) { - ret = -EINVAL; - kfree_sensitive(new_p); + ret = getoptions(datablob, p, options); + if (ret < 0) goto out; - } + dump_options(options); - if (!new_o->keyhandle) { + if (!options->keyhandle && !tpm2) { ret = -EINVAL; - kfree_sensitive(new_p); goto out; } - /* copy old key values, and reseal with new pcrs */ - new_p->migratable = p->migratable; - new_p->key_len = p->key_len; - memcpy(new_p->key, p->key, p->key_len); - dump_payload(p); - dump_payload(new_p); + if (tpm2) + ret = tpm2_unseal_trusted(chip, p, options); + else + ret = key_unseal(p, options); + if (ret < 0) + pr_info("key_unseal failed (%d)\n", ret); - ret = key_seal(new_p, new_o); - if (ret < 0) { - pr_info("trusted_key: key_seal failed (%d)\n", ret); - kfree_sensitive(new_p); - goto out; - } - if (new_o->pcrlock) { - ret = pcrlock(new_o->pcrlock); + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); if (ret < 0) { - pr_info("trusted_key: pcrlock failed (%d)\n", ret); - kfree_sensitive(new_p); + pr_info("pcrlock failed (%d)\n", ret); goto out; } } - rcu_assign_keypointer(key, new_p); - call_rcu(&p->rcu, trusted_rcu_free); out: - kfree_sensitive(datablob); - kfree_sensitive(new_o); + kfree_sensitive(options); return ret; } -/* - * trusted_read - copy the sealed blob data to userspace in hex. - * On success, return to userspace the trusted key datablob size. - */ -static long trusted_read(const struct key *key, char *buffer, - size_t buflen) -{ - const struct trusted_key_payload *p; - char *bufp; - int i; - - p = dereference_key_locked(key); - if (!p) - return -EINVAL; - - if (buffer && buflen >= 2 * p->blob_len) { - bufp = buffer; - for (i = 0; i < p->blob_len; i++) - bufp = hex_byte_pack(bufp, p->blob[i]); - } - return 2 * p->blob_len; -} - -/* - * trusted_destroy - clear and free the key's payload - */ -static void trusted_destroy(struct key *key) +static int trusted_tpm_get_random(unsigned char *key, size_t key_len) { - kfree_sensitive(key->payload.data[0]); + return tpm_get_random(chip, key, key_len); } -struct key_type key_type_trusted = { - .name = "trusted", - .instantiate = trusted_instantiate, - .update = trusted_update, - .destroy = trusted_destroy, - .describe = user_describe, - .read = trusted_read, -}; - -EXPORT_SYMBOL_GPL(key_type_trusted); - static void trusted_shash_release(void) { if (hashalg) @@ -1196,14 +990,14 @@ static int __init trusted_shash_alloc(void) hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); if (IS_ERR(hmacalg)) { - pr_info("trusted_key: could not allocate crypto %s\n", + pr_info("could not allocate crypto %s\n", hmac_alg); return PTR_ERR(hmacalg); } hashalg = crypto_alloc_shash(hash_alg, 0, 0); if (IS_ERR(hashalg)) { - pr_info("trusted_key: could not allocate crypto %s\n", + pr_info("could not allocate crypto %s\n", hash_alg); ret = PTR_ERR(hashalg); goto hashalg_fail; @@ -1231,16 +1025,13 @@ static int __init init_digests(void) return 0; } -static int __init init_trusted(void) +static int __init trusted_tpm_init(void) { int ret; - /* encrypted_keys.ko depends on successful load of this module even if - * TPM is not used. - */ chip = tpm_default_chip(); if (!chip) - return 0; + return -ENODEV; ret = init_digests(); if (ret < 0) @@ -1261,7 +1052,7 @@ err_put: return ret; } -static void __exit cleanup_trusted(void) +static void trusted_tpm_exit(void) { if (chip) { put_device(&chip->dev); @@ -1271,7 +1062,11 @@ static void __exit cleanup_trusted(void) } } -late_initcall(init_trusted); -module_exit(cleanup_trusted); - -MODULE_LICENSE("GPL"); +struct trusted_key_ops trusted_key_tpm_ops = { + .migratable = 1, /* migratable by default */ + .init = trusted_tpm_init, + .seal = trusted_tpm_seal, + .unseal = trusted_tpm_unseal, + .get_random = trusted_tpm_get_random, + .exit = trusted_tpm_exit, +}; diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index c87c4df8703d..617fabd4d913 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -4,6 +4,8 @@ * Copyright (C) 2014 Intel Corporation */ +#include <linux/asn1_encoder.h> +#include <linux/oid_registry.h> #include <linux/string.h> #include <linux/err.h> #include <linux/tpm.h> @@ -12,6 +14,10 @@ #include <keys/trusted-type.h> #include <keys/trusted_tpm.h> +#include <asm/unaligned.h> + +#include "tpm2key.asn1.h" + static struct tpm2_hash tpm2_hash_map[] = { {HASH_ALGO_SHA1, TPM_ALG_SHA1}, {HASH_ALGO_SHA256, TPM_ALG_SHA256}, @@ -20,6 +26,165 @@ static struct tpm2_hash tpm2_hash_map[] = { {HASH_ALGO_SM3_256, TPM_ALG_SM3_256}, }; +static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 }; + +static int tpm2_key_encode(struct trusted_key_payload *payload, + struct trusted_key_options *options, + u8 *src, u32 len) +{ + const int SCRATCH_SIZE = PAGE_SIZE; + u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); + u8 *work = scratch, *work1; + u8 *end_work = scratch + SCRATCH_SIZE; + u8 *priv, *pub; + u16 priv_len, pub_len; + + priv_len = get_unaligned_be16(src) + 2; + priv = src; + + src += priv_len; + + pub_len = get_unaligned_be16(src) + 2; + pub = src; + + if (!scratch) + return -ENOMEM; + + work = asn1_encode_oid(work, end_work, tpm2key_oid, + asn1_oid_len(tpm2key_oid)); + + if (options->blobauth_len == 0) { + unsigned char bool[3], *w = bool; + /* tag 0 is emptyAuth */ + w = asn1_encode_boolean(w, w + sizeof(bool), true); + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) + return PTR_ERR(w); + work = asn1_encode_tag(work, end_work, 0, bool, w - bool); + } + + /* + * Assume both octet strings will encode to a 2 byte definite length + * + * Note: For a well behaved TPM, this warning should never + * trigger, so if it does there's something nefarious going on + */ + if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, + "BUG: scratch buffer is too small")) + return -EINVAL; + + work = asn1_encode_integer(work, end_work, options->keyhandle); + work = asn1_encode_octet_string(work, end_work, pub, pub_len); + work = asn1_encode_octet_string(work, end_work, priv, priv_len); + + work1 = payload->blob; + work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), + scratch, work - scratch); + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) + return PTR_ERR(work1); + + return work1 - payload->blob; +} + +struct tpm2_key_context { + u32 parent; + const u8 *pub; + u32 pub_len; + const u8 *priv; + u32 priv_len; +}; + +static int tpm2_key_decode(struct trusted_key_payload *payload, + struct trusted_key_options *options, + u8 **buf) +{ + int ret; + struct tpm2_key_context ctx; + u8 *blob; + + memset(&ctx, 0, sizeof(ctx)); + + ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob, + payload->blob_len); + if (ret < 0) + return ret; + + if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE) + return -EINVAL; + + blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL); + if (!blob) + return -ENOMEM; + + *buf = blob; + options->keyhandle = ctx.parent; + + memcpy(blob, ctx.priv, ctx.priv_len); + blob += ctx.priv_len; + + memcpy(blob, ctx.pub, ctx.pub_len); + + return 0; +} + +int tpm2_key_parent(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + const u8 *v = value; + int i; + + ctx->parent = 0; + for (i = 0; i < vlen; i++) { + ctx->parent <<= 8; + ctx->parent |= v[i]; + } + + return 0; +} + +int tpm2_key_type(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + enum OID oid = look_up_OID(value, vlen); + + if (oid != OID_TPMSealedData) { + char buffer[50]; + + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_debug("OID is \"%s\" which is not TPMSealedData\n", + buffer); + return -EINVAL; + } + + return 0; +} + +int tpm2_key_pub(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + + ctx->pub = value; + ctx->pub_len = vlen; + + return 0; +} + +int tpm2_key_priv(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + + ctx->priv = value; + ctx->priv_len = vlen; + + return 0; +} + /** * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer. * @@ -63,9 +228,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload, struct trusted_key_options *options) { - unsigned int blob_len; + int blob_len = 0; struct tpm_buf buf; u32 hash; + u32 flags; int i; int rc; @@ -79,6 +245,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip, if (i == ARRAY_SIZE(tpm2_hash_map)) return -EINVAL; + if (!options->keyhandle) + return -EINVAL; + rc = tpm_try_get_ops(chip); if (rc) return rc; @@ -97,29 +266,32 @@ int tpm2_seal_trusted(struct tpm_chip *chip, TPM_DIGEST_SIZE); /* sensitive */ - tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1); + tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len); + + tpm_buf_append_u16(&buf, options->blobauth_len); + if (options->blobauth_len) + tpm_buf_append(&buf, options->blobauth, options->blobauth_len); - tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE); - tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE); - tpm_buf_append_u16(&buf, payload->key_len + 1); + tpm_buf_append_u16(&buf, payload->key_len); tpm_buf_append(&buf, payload->key, payload->key_len); - tpm_buf_append_u8(&buf, payload->migratable); /* public */ tpm_buf_append_u16(&buf, 14 + options->policydigest_len); tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH); tpm_buf_append_u16(&buf, hash); + /* key properties */ + flags = 0; + flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH; + flags |= payload->migratable ? (TPM2_OA_FIXED_TPM | + TPM2_OA_FIXED_PARENT) : 0; + tpm_buf_append_u32(&buf, flags); + /* policy */ - if (options->policydigest_len) { - tpm_buf_append_u32(&buf, 0); - tpm_buf_append_u16(&buf, options->policydigest_len); + tpm_buf_append_u16(&buf, options->policydigest_len); + if (options->policydigest_len) tpm_buf_append(&buf, options->policydigest, options->policydigest_len); - } else { - tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH); - tpm_buf_append_u16(&buf, 0); - } /* public parameters */ tpm_buf_append_u16(&buf, TPM_ALG_NULL); @@ -150,8 +322,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len); - payload->blob_len = blob_len; + blob_len = tpm2_key_encode(payload, options, + &buf.data[TPM_HEADER_SIZE + 4], + blob_len); out: tpm_buf_destroy(&buf); @@ -162,6 +335,10 @@ out: else rc = -EPERM; } + if (blob_len < 0) + return blob_len; + + payload->blob_len = blob_len; tpm_put_ops(chip); return rc; @@ -189,13 +366,45 @@ static int tpm2_load_cmd(struct tpm_chip *chip, unsigned int private_len; unsigned int public_len; unsigned int blob_len; + u8 *blob, *pub; int rc; + u32 attrs; + + rc = tpm2_key_decode(payload, options, &blob); + if (rc) { + /* old form */ + blob = payload->blob; + payload->old_format = 1; + } + + /* new format carries keyhandle but old format doesn't */ + if (!options->keyhandle) + return -EINVAL; - private_len = be16_to_cpup((__be16 *) &payload->blob[0]); - if (private_len > (payload->blob_len - 2)) + /* must be big enough for at least the two be16 size counts */ + if (payload->blob_len < 4) + return -EINVAL; + + private_len = get_unaligned_be16(blob); + + /* must be big enough for following public_len */ + if (private_len + 2 + 2 > (payload->blob_len)) + return -E2BIG; + + public_len = get_unaligned_be16(blob + 2 + private_len); + if (private_len + 2 + public_len + 2 > payload->blob_len) return -E2BIG; - public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]); + pub = blob + 2 + private_len + 2; + /* key attributes are always at offset 4 */ + attrs = get_unaligned_be32(pub + 4); + + if ((attrs & (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT)) == + (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT)) + payload->migratable = 0; + else + payload->migratable = 1; + blob_len = private_len + public_len + 4; if (blob_len > payload->blob_len) return -E2BIG; @@ -211,7 +420,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip, options->keyauth /* hmac */, TPM_DIGEST_SIZE); - tpm_buf_append(&buf, payload->blob, blob_len); + tpm_buf_append(&buf, blob, blob_len); if (buf.flags & TPM_BUF_OVERFLOW) { rc = -E2BIG; @@ -224,6 +433,8 @@ static int tpm2_load_cmd(struct tpm_chip *chip, (__be32 *) &buf.data[TPM_HEADER_SIZE]); out: + if (blob != payload->blob) + kfree(blob); tpm_buf_destroy(&buf); if (rc > 0) @@ -265,7 +476,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, NULL /* nonce */, 0, TPM2_SA_CONTINUE_SESSION, options->blobauth /* hmac */, - TPM_DIGEST_SIZE); + options->blobauth_len); rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); if (rc > 0) @@ -274,7 +485,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, if (!rc) { data_len = be16_to_cpup( (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); - if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) { + if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE) { rc = -EFAULT; goto out; } @@ -285,9 +496,19 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, } data = &buf.data[TPM_HEADER_SIZE + 6]; - memcpy(payload->key, data, data_len - 1); - payload->key_len = data_len - 1; - payload->migratable = data[data_len - 1]; + if (payload->old_format) { + /* migratable flag is at the end of the key */ + memcpy(payload->key, data, data_len - 1); + payload->key_len = data_len - 1; + payload->migratable = data[data_len - 1]; + } else { + /* + * migratable flag already collected from key + * attributes + */ + memcpy(payload->key, data, data_len); + payload->key_len = data_len; + } } out: diff --git a/security/landlock/Kconfig b/security/landlock/Kconfig new file mode 100644 index 000000000000..8e33c4e8ffb8 --- /dev/null +++ b/security/landlock/Kconfig @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config SECURITY_LANDLOCK + bool "Landlock support" + depends on SECURITY && !ARCH_EPHEMERAL_INODES + select SECURITY_PATH + help + Landlock is a sandboxing mechanism that enables processes to restrict + themselves (and their future children) by gradually enforcing + tailored access control policies. A Landlock security policy is a + set of access rights (e.g. open a file in read-only, make a + directory, etc.) tied to a file hierarchy. Such policy can be + configured and enforced by any processes for themselves using the + dedicated system calls: landlock_create_ruleset(), + landlock_add_rule(), and landlock_restrict_self(). + + See Documentation/userspace-api/landlock.rst for further information. + + If you are unsure how to answer this question, answer N. Otherwise, + you should also prepend "landlock," to the content of CONFIG_LSM to + enable Landlock at boot time. diff --git a/security/landlock/Makefile b/security/landlock/Makefile new file mode 100644 index 000000000000..7bbd2f413b3e --- /dev/null +++ b/security/landlock/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_SECURITY_LANDLOCK) := landlock.o + +landlock-y := setup.o syscalls.o object.o ruleset.o \ + cred.o ptrace.o fs.o diff --git a/security/landlock/common.h b/security/landlock/common.h new file mode 100644 index 000000000000..5dc0fe15707d --- /dev/null +++ b/security/landlock/common.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Common constants and helpers + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_COMMON_H +#define _SECURITY_LANDLOCK_COMMON_H + +#define LANDLOCK_NAME "landlock" + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) LANDLOCK_NAME ": " fmt + +#endif /* _SECURITY_LANDLOCK_COMMON_H */ diff --git a/security/landlock/cred.c b/security/landlock/cred.c new file mode 100644 index 000000000000..6725af24c684 --- /dev/null +++ b/security/landlock/cred.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Credential hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/cred.h> +#include <linux/lsm_hooks.h> + +#include "common.h" +#include "cred.h" +#include "ruleset.h" +#include "setup.h" + +static int hook_cred_prepare(struct cred *const new, + const struct cred *const old, const gfp_t gfp) +{ + struct landlock_ruleset *const old_dom = landlock_cred(old)->domain; + + if (old_dom) { + landlock_get_ruleset(old_dom); + landlock_cred(new)->domain = old_dom; + } + return 0; +} + +static void hook_cred_free(struct cred *const cred) +{ + struct landlock_ruleset *const dom = landlock_cred(cred)->domain; + + if (dom) + landlock_put_ruleset_deferred(dom); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(cred_prepare, hook_cred_prepare), + LSM_HOOK_INIT(cred_free, hook_cred_free), +}; + +__init void landlock_add_cred_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/cred.h b/security/landlock/cred.h new file mode 100644 index 000000000000..5f99d3decade --- /dev/null +++ b/security/landlock/cred.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Credential hooks + * + * Copyright © 2019-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_CRED_H +#define _SECURITY_LANDLOCK_CRED_H + +#include <linux/cred.h> +#include <linux/init.h> +#include <linux/rcupdate.h> + +#include "ruleset.h" +#include "setup.h" + +struct landlock_cred_security { + struct landlock_ruleset *domain; +}; + +static inline struct landlock_cred_security *landlock_cred( + const struct cred *cred) +{ + return cred->security + landlock_blob_sizes.lbs_cred; +} + +static inline const struct landlock_ruleset *landlock_get_current_domain(void) +{ + return landlock_cred(current_cred())->domain; +} + +/* + * The call needs to come from an RCU read-side critical section. + */ +static inline const struct landlock_ruleset *landlock_get_task_domain( + const struct task_struct *const task) +{ + return landlock_cred(__task_cred(task))->domain; +} + +static inline bool landlocked(const struct task_struct *const task) +{ + bool has_dom; + + if (task == current) + return !!landlock_get_current_domain(); + + rcu_read_lock(); + has_dom = !!landlock_get_task_domain(task); + rcu_read_unlock(); + return has_dom; +} + +__init void landlock_add_cred_hooks(void); + +#endif /* _SECURITY_LANDLOCK_CRED_H */ diff --git a/security/landlock/fs.c b/security/landlock/fs.c new file mode 100644 index 000000000000..97b8e421f617 --- /dev/null +++ b/security/landlock/fs.c @@ -0,0 +1,692 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Filesystem management and hooks + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/atomic.h> +#include <linux/bitops.h> +#include <linux/bits.h> +#include <linux/compiler_types.h> +#include <linux/dcache.h> +#include <linux/err.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/list.h> +#include <linux/lsm_hooks.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/path.h> +#include <linux/rcupdate.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/types.h> +#include <linux/wait_bit.h> +#include <linux/workqueue.h> +#include <uapi/linux/landlock.h> + +#include "common.h" +#include "cred.h" +#include "fs.h" +#include "limits.h" +#include "object.h" +#include "ruleset.h" +#include "setup.h" + +/* Underlying object management */ + +static void release_inode(struct landlock_object *const object) + __releases(object->lock) +{ + struct inode *const inode = object->underobj; + struct super_block *sb; + + if (!inode) { + spin_unlock(&object->lock); + return; + } + + /* + * Protects against concurrent use by hook_sb_delete() of the reference + * to the underlying inode. + */ + object->underobj = NULL; + /* + * Makes sure that if the filesystem is concurrently unmounted, + * hook_sb_delete() will wait for us to finish iput(). + */ + sb = inode->i_sb; + atomic_long_inc(&landlock_superblock(sb)->inode_refs); + spin_unlock(&object->lock); + /* + * Because object->underobj was not NULL, hook_sb_delete() and + * get_inode_object() guarantee that it is safe to reset + * landlock_inode(inode)->object while it is not NULL. It is therefore + * not necessary to lock inode->i_lock. + */ + rcu_assign_pointer(landlock_inode(inode)->object, NULL); + /* + * Now, new rules can safely be tied to @inode with get_inode_object(). + */ + + iput(inode); + if (atomic_long_dec_and_test(&landlock_superblock(sb)->inode_refs)) + wake_up_var(&landlock_superblock(sb)->inode_refs); +} + +static const struct landlock_object_underops landlock_fs_underops = { + .release = release_inode +}; + +/* Ruleset management */ + +static struct landlock_object *get_inode_object(struct inode *const inode) +{ + struct landlock_object *object, *new_object; + struct landlock_inode_security *inode_sec = landlock_inode(inode); + + rcu_read_lock(); +retry: + object = rcu_dereference(inode_sec->object); + if (object) { + if (likely(refcount_inc_not_zero(&object->usage))) { + rcu_read_unlock(); + return object; + } + /* + * We are racing with release_inode(), the object is going + * away. Wait for release_inode(), then retry. + */ + spin_lock(&object->lock); + spin_unlock(&object->lock); + goto retry; + } + rcu_read_unlock(); + + /* + * If there is no object tied to @inode, then create a new one (without + * holding any locks). + */ + new_object = landlock_create_object(&landlock_fs_underops, inode); + if (IS_ERR(new_object)) + return new_object; + + /* + * Protects against concurrent calls to get_inode_object() or + * hook_sb_delete(). + */ + spin_lock(&inode->i_lock); + if (unlikely(rcu_access_pointer(inode_sec->object))) { + /* Someone else just created the object, bail out and retry. */ + spin_unlock(&inode->i_lock); + kfree(new_object); + + rcu_read_lock(); + goto retry; + } + + /* + * @inode will be released by hook_sb_delete() on its superblock + * shutdown, or by release_inode() when no more ruleset references the + * related object. + */ + ihold(inode); + rcu_assign_pointer(inode_sec->object, new_object); + spin_unlock(&inode->i_lock); + return new_object; +} + +/* All access rights that can be tied to files. */ +#define ACCESS_FILE ( \ + LANDLOCK_ACCESS_FS_EXECUTE | \ + LANDLOCK_ACCESS_FS_WRITE_FILE | \ + LANDLOCK_ACCESS_FS_READ_FILE) + +/* + * @path: Should have been checked by get_path_from_fd(). + */ +int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, + const struct path *const path, u32 access_rights) +{ + int err; + struct landlock_object *object; + + /* Files only get access rights that make sense. */ + if (!d_is_dir(path->dentry) && (access_rights | ACCESS_FILE) != + ACCESS_FILE) + return -EINVAL; + if (WARN_ON_ONCE(ruleset->num_layers != 1)) + return -EINVAL; + + /* Transforms relative access rights to absolute ones. */ + access_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->fs_access_masks[0]; + object = get_inode_object(d_backing_inode(path->dentry)); + if (IS_ERR(object)) + return PTR_ERR(object); + mutex_lock(&ruleset->lock); + err = landlock_insert_rule(ruleset, object, access_rights); + mutex_unlock(&ruleset->lock); + /* + * No need to check for an error because landlock_insert_rule() + * increments the refcount for the new object if needed. + */ + landlock_put_object(object); + return err; +} + +/* Access-control management */ + +static inline u64 unmask_layers( + const struct landlock_ruleset *const domain, + const struct path *const path, const u32 access_request, + u64 layer_mask) +{ + const struct landlock_rule *rule; + const struct inode *inode; + size_t i; + + if (d_is_negative(path->dentry)) + /* Ignore nonexistent leafs. */ + return layer_mask; + inode = d_backing_inode(path->dentry); + rcu_read_lock(); + rule = landlock_find_rule(domain, + rcu_dereference(landlock_inode(inode)->object)); + rcu_read_unlock(); + if (!rule) + return layer_mask; + + /* + * An access is granted if, for each policy layer, at least one rule + * encountered on the pathwalk grants the requested accesses, + * regardless of their position in the layer stack. We must then check + * the remaining layers for each inode, from the first added layer to + * the last one. + */ + for (i = 0; i < rule->num_layers; i++) { + const struct landlock_layer *const layer = &rule->layers[i]; + const u64 layer_level = BIT_ULL(layer->level - 1); + + /* Checks that the layer grants access to the full request. */ + if ((layer->access & access_request) == access_request) { + layer_mask &= ~layer_level; + + if (layer_mask == 0) + return layer_mask; + } + } + return layer_mask; +} + +static int check_access_path(const struct landlock_ruleset *const domain, + const struct path *const path, u32 access_request) +{ + bool allowed = false; + struct path walker_path; + u64 layer_mask; + size_t i; + + /* Make sure all layers can be checked. */ + BUILD_BUG_ON(BITS_PER_TYPE(layer_mask) < LANDLOCK_MAX_NUM_LAYERS); + + if (!access_request) + return 0; + if (WARN_ON_ONCE(!domain || !path)) + return 0; + /* + * Allows access to pseudo filesystems that will never be mountable + * (e.g. sockfs, pipefs), but can still be reachable through + * /proc/<pid>/fd/<file-descriptor> . + */ + if ((path->dentry->d_sb->s_flags & SB_NOUSER) || + (d_is_positive(path->dentry) && + unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))) + return 0; + if (WARN_ON_ONCE(domain->num_layers < 1)) + return -EACCES; + + /* Saves all layers handling a subset of requested accesses. */ + layer_mask = 0; + for (i = 0; i < domain->num_layers; i++) { + if (domain->fs_access_masks[i] & access_request) + layer_mask |= BIT_ULL(i); + } + /* An access request not handled by the domain is allowed. */ + if (layer_mask == 0) + return 0; + + walker_path = *path; + path_get(&walker_path); + /* + * We need to walk through all the hierarchy to not miss any relevant + * restriction. + */ + while (true) { + struct dentry *parent_dentry; + + layer_mask = unmask_layers(domain, &walker_path, + access_request, layer_mask); + if (layer_mask == 0) { + /* Stops when a rule from each layer grants access. */ + allowed = true; + break; + } + +jump_up: + if (walker_path.dentry == walker_path.mnt->mnt_root) { + if (follow_up(&walker_path)) { + /* Ignores hidden mount points. */ + goto jump_up; + } else { + /* + * Stops at the real root. Denies access + * because not all layers have granted access. + */ + allowed = false; + break; + } + } + if (unlikely(IS_ROOT(walker_path.dentry))) { + /* + * Stops at disconnected root directories. Only allows + * access to internal filesystems (e.g. nsfs, which is + * reachable through /proc/<pid>/ns/<namespace>). + */ + allowed = !!(walker_path.mnt->mnt_flags & MNT_INTERNAL); + break; + } + parent_dentry = dget_parent(walker_path.dentry); + dput(walker_path.dentry); + walker_path.dentry = parent_dentry; + } + path_put(&walker_path); + return allowed ? 0 : -EACCES; +} + +static inline int current_check_access_path(const struct path *const path, + const u32 access_request) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + return check_access_path(dom, path, access_request); +} + +/* Inode hooks */ + +static void hook_inode_free_security(struct inode *const inode) +{ + /* + * All inodes must already have been untied from their object by + * release_inode() or hook_sb_delete(). + */ + WARN_ON_ONCE(landlock_inode(inode)->object); +} + +/* Super-block hooks */ + +/* + * Release the inodes used in a security policy. + * + * Cf. fsnotify_unmount_inodes() and invalidate_inodes() + */ +static void hook_sb_delete(struct super_block *const sb) +{ + struct inode *inode, *prev_inode = NULL; + + if (!landlock_initialized) + return; + + spin_lock(&sb->s_inode_list_lock); + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { + struct landlock_object *object; + + /* Only handles referenced inodes. */ + if (!atomic_read(&inode->i_count)) + continue; + + /* + * Protects against concurrent modification of inode (e.g. + * from get_inode_object()). + */ + spin_lock(&inode->i_lock); + /* + * Checks I_FREEING and I_WILL_FREE to protect against a race + * condition when release_inode() just called iput(), which + * could lead to a NULL dereference of inode->security or a + * second call to iput() for the same Landlock object. Also + * checks I_NEW because such inode cannot be tied to an object. + */ + if (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW)) { + spin_unlock(&inode->i_lock); + continue; + } + + rcu_read_lock(); + object = rcu_dereference(landlock_inode(inode)->object); + if (!object) { + rcu_read_unlock(); + spin_unlock(&inode->i_lock); + continue; + } + /* Keeps a reference to this inode until the next loop walk. */ + __iget(inode); + spin_unlock(&inode->i_lock); + + /* + * If there is no concurrent release_inode() ongoing, then we + * are in charge of calling iput() on this inode, otherwise we + * will just wait for it to finish. + */ + spin_lock(&object->lock); + if (object->underobj == inode) { + object->underobj = NULL; + spin_unlock(&object->lock); + rcu_read_unlock(); + + /* + * Because object->underobj was not NULL, + * release_inode() and get_inode_object() guarantee + * that it is safe to reset + * landlock_inode(inode)->object while it is not NULL. + * It is therefore not necessary to lock inode->i_lock. + */ + rcu_assign_pointer(landlock_inode(inode)->object, NULL); + /* + * At this point, we own the ihold() reference that was + * originally set up by get_inode_object() and the + * __iget() reference that we just set in this loop + * walk. Therefore the following call to iput() will + * not sleep nor drop the inode because there is now at + * least two references to it. + */ + iput(inode); + } else { + spin_unlock(&object->lock); + rcu_read_unlock(); + } + + if (prev_inode) { + /* + * At this point, we still own the __iget() reference + * that we just set in this loop walk. Therefore we + * can drop the list lock and know that the inode won't + * disappear from under us until the next loop walk. + */ + spin_unlock(&sb->s_inode_list_lock); + /* + * We can now actually put the inode reference from the + * previous loop walk, which is not needed anymore. + */ + iput(prev_inode); + cond_resched(); + spin_lock(&sb->s_inode_list_lock); + } + prev_inode = inode; + } + spin_unlock(&sb->s_inode_list_lock); + + /* Puts the inode reference from the last loop walk, if any. */ + if (prev_inode) + iput(prev_inode); + /* Waits for pending iput() in release_inode(). */ + wait_var_event(&landlock_superblock(sb)->inode_refs, !atomic_long_read( + &landlock_superblock(sb)->inode_refs)); +} + +/* + * Because a Landlock security policy is defined according to the filesystem + * topology (i.e. the mount namespace), changing it may grant access to files + * not previously allowed. + * + * To make it simple, deny any filesystem topology modification by landlocked + * processes. Non-landlocked processes may still change the namespace of a + * landlocked process, but this kind of threat must be handled by a system-wide + * access-control security policy. + * + * This could be lifted in the future if Landlock can safely handle mount + * namespace updates requested by a landlocked process. Indeed, we could + * update the current domain (which is currently read-only) by taking into + * account the accesses of the source and the destination of a new mount point. + * However, it would also require to make all the child domains dynamically + * inherit these new constraints. Anyway, for backward compatibility reasons, + * a dedicated user space option would be required (e.g. as a ruleset flag). + */ +static int hook_sb_mount(const char *const dev_name, + const struct path *const path, const char *const type, + const unsigned long flags, void *const data) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +static int hook_move_mount(const struct path *const from_path, + const struct path *const to_path) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* + * Removing a mount point may reveal a previously hidden file hierarchy, which + * may then grant access to files, which may have previously been forbidden. + */ +static int hook_sb_umount(struct vfsmount *const mnt, const int flags) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* + * pivot_root(2), like mount(2), changes the current mount namespace. It must + * then be forbidden for a landlocked process. + * + * However, chroot(2) may be allowed because it only changes the relative root + * directory of the current process. Moreover, it can be used to restrict the + * view of the filesystem. + */ +static int hook_sb_pivotroot(const struct path *const old_path, + const struct path *const new_path) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* Path hooks */ + +static inline u32 get_mode_access(const umode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFLNK: + return LANDLOCK_ACCESS_FS_MAKE_SYM; + case 0: + /* A zero mode translates to S_IFREG. */ + case S_IFREG: + return LANDLOCK_ACCESS_FS_MAKE_REG; + case S_IFDIR: + return LANDLOCK_ACCESS_FS_MAKE_DIR; + case S_IFCHR: + return LANDLOCK_ACCESS_FS_MAKE_CHAR; + case S_IFBLK: + return LANDLOCK_ACCESS_FS_MAKE_BLOCK; + case S_IFIFO: + return LANDLOCK_ACCESS_FS_MAKE_FIFO; + case S_IFSOCK: + return LANDLOCK_ACCESS_FS_MAKE_SOCK; + default: + WARN_ON_ONCE(1); + return 0; + } +} + +/* + * Creating multiple links or renaming may lead to privilege escalations if not + * handled properly. Indeed, we must be sure that the source doesn't gain more + * privileges by being accessible from the destination. This is getting more + * complex when dealing with multiple layers. The whole picture can be seen as + * a multilayer partial ordering problem. A future version of Landlock will + * deal with that. + */ +static int hook_path_link(struct dentry *const old_dentry, + const struct path *const new_dir, + struct dentry *const new_dentry) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + /* The mount points are the same for old and new paths, cf. EXDEV. */ + if (old_dentry->d_parent != new_dir->dentry) + /* Gracefully forbids reparenting. */ + return -EXDEV; + if (unlikely(d_is_negative(old_dentry))) + return -ENOENT; + return check_access_path(dom, new_dir, + get_mode_access(d_backing_inode(old_dentry)->i_mode)); +} + +static inline u32 maybe_remove(const struct dentry *const dentry) +{ + if (d_is_negative(dentry)) + return 0; + return d_is_dir(dentry) ? LANDLOCK_ACCESS_FS_REMOVE_DIR : + LANDLOCK_ACCESS_FS_REMOVE_FILE; +} + +static int hook_path_rename(const struct path *const old_dir, + struct dentry *const old_dentry, + const struct path *const new_dir, + struct dentry *const new_dentry) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + /* The mount points are the same for old and new paths, cf. EXDEV. */ + if (old_dir->dentry != new_dir->dentry) + /* Gracefully forbids reparenting. */ + return -EXDEV; + if (unlikely(d_is_negative(old_dentry))) + return -ENOENT; + /* RENAME_EXCHANGE is handled because directories are the same. */ + return check_access_path(dom, old_dir, maybe_remove(old_dentry) | + maybe_remove(new_dentry) | + get_mode_access(d_backing_inode(old_dentry)->i_mode)); +} + +static int hook_path_mkdir(const struct path *const dir, + struct dentry *const dentry, const umode_t mode) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_DIR); +} + +static int hook_path_mknod(const struct path *const dir, + struct dentry *const dentry, const umode_t mode, + const unsigned int dev) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + return check_access_path(dom, dir, get_mode_access(mode)); +} + +static int hook_path_symlink(const struct path *const dir, + struct dentry *const dentry, const char *const old_name) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_SYM); +} + +static int hook_path_unlink(const struct path *const dir, + struct dentry *const dentry) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_FILE); +} + +static int hook_path_rmdir(const struct path *const dir, + struct dentry *const dentry) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_DIR); +} + +/* File hooks */ + +static inline u32 get_file_access(const struct file *const file) +{ + u32 access = 0; + + if (file->f_mode & FMODE_READ) { + /* A directory can only be opened in read mode. */ + if (S_ISDIR(file_inode(file)->i_mode)) + return LANDLOCK_ACCESS_FS_READ_DIR; + access = LANDLOCK_ACCESS_FS_READ_FILE; + } + if (file->f_mode & FMODE_WRITE) + access |= LANDLOCK_ACCESS_FS_WRITE_FILE; + /* __FMODE_EXEC is indeed part of f_flags, not f_mode. */ + if (file->f_flags & __FMODE_EXEC) + access |= LANDLOCK_ACCESS_FS_EXECUTE; + return access; +} + +static int hook_file_open(struct file *const file) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + /* + * Because a file may be opened with O_PATH, get_file_access() may + * return 0. This case will be handled with a future Landlock + * evolution. + */ + return check_access_path(dom, &file->f_path, get_file_access(file)); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(inode_free_security, hook_inode_free_security), + + LSM_HOOK_INIT(sb_delete, hook_sb_delete), + LSM_HOOK_INIT(sb_mount, hook_sb_mount), + LSM_HOOK_INIT(move_mount, hook_move_mount), + LSM_HOOK_INIT(sb_umount, hook_sb_umount), + LSM_HOOK_INIT(sb_remount, hook_sb_remount), + LSM_HOOK_INIT(sb_pivotroot, hook_sb_pivotroot), + + LSM_HOOK_INIT(path_link, hook_path_link), + LSM_HOOK_INIT(path_rename, hook_path_rename), + LSM_HOOK_INIT(path_mkdir, hook_path_mkdir), + LSM_HOOK_INIT(path_mknod, hook_path_mknod), + LSM_HOOK_INIT(path_symlink, hook_path_symlink), + LSM_HOOK_INIT(path_unlink, hook_path_unlink), + LSM_HOOK_INIT(path_rmdir, hook_path_rmdir), + + LSM_HOOK_INIT(file_open, hook_file_open), +}; + +__init void landlock_add_fs_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/fs.h b/security/landlock/fs.h new file mode 100644 index 000000000000..187284b421c9 --- /dev/null +++ b/security/landlock/fs.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Filesystem management and hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_FS_H +#define _SECURITY_LANDLOCK_FS_H + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/rcupdate.h> + +#include "ruleset.h" +#include "setup.h" + +/** + * struct landlock_inode_security - Inode security blob + * + * Enable to reference a &struct landlock_object tied to an inode (i.e. + * underlying object). + */ +struct landlock_inode_security { + /** + * @object: Weak pointer to an allocated object. All assignments of a + * new object are protected by the underlying inode->i_lock. However, + * atomically disassociating @object from the inode is only protected + * by @object->lock, from the time @object's usage refcount drops to + * zero to the time this pointer is nulled out (cf. release_inode() and + * hook_sb_delete()). Indeed, such disassociation doesn't require + * inode->i_lock thanks to the careful rcu_access_pointer() check + * performed by get_inode_object(). + */ + struct landlock_object __rcu *object; +}; + +/** + * struct landlock_superblock_security - Superblock security blob + * + * Enable hook_sb_delete() to wait for concurrent calls to release_inode(). + */ +struct landlock_superblock_security { + /** + * @inode_refs: Number of pending inodes (from this superblock) that + * are being released by release_inode(). + * Cf. struct super_block->s_fsnotify_inode_refs . + */ + atomic_long_t inode_refs; +}; + +static inline struct landlock_inode_security *landlock_inode( + const struct inode *const inode) +{ + return inode->i_security + landlock_blob_sizes.lbs_inode; +} + +static inline struct landlock_superblock_security *landlock_superblock( + const struct super_block *const superblock) +{ + return superblock->s_security + landlock_blob_sizes.lbs_superblock; +} + +__init void landlock_add_fs_hooks(void); + +int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, + const struct path *const path, u32 access_hierarchy); + +#endif /* _SECURITY_LANDLOCK_FS_H */ diff --git a/security/landlock/limits.h b/security/landlock/limits.h new file mode 100644 index 000000000000..2a0a1095ee27 --- /dev/null +++ b/security/landlock/limits.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Limits for different components + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_LIMITS_H +#define _SECURITY_LANDLOCK_LIMITS_H + +#include <linux/limits.h> +#include <uapi/linux/landlock.h> + +#define LANDLOCK_MAX_NUM_LAYERS 64 +#define LANDLOCK_MAX_NUM_RULES U32_MAX + +#define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_MAKE_SYM +#define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) + +#endif /* _SECURITY_LANDLOCK_LIMITS_H */ diff --git a/security/landlock/object.c b/security/landlock/object.c new file mode 100644 index 000000000000..d674fdf9ff04 --- /dev/null +++ b/security/landlock/object.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Object management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/bug.h> +#include <linux/compiler_types.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/rcupdate.h> +#include <linux/refcount.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "object.h" + +struct landlock_object *landlock_create_object( + const struct landlock_object_underops *const underops, + void *const underobj) +{ + struct landlock_object *new_object; + + if (WARN_ON_ONCE(!underops || !underobj)) + return ERR_PTR(-ENOENT); + new_object = kzalloc(sizeof(*new_object), GFP_KERNEL_ACCOUNT); + if (!new_object) + return ERR_PTR(-ENOMEM); + refcount_set(&new_object->usage, 1); + spin_lock_init(&new_object->lock); + new_object->underops = underops; + new_object->underobj = underobj; + return new_object; +} + +/* + * The caller must own the object (i.e. thanks to object->usage) to safely put + * it. + */ +void landlock_put_object(struct landlock_object *const object) +{ + /* + * The call to @object->underops->release(object) might sleep, e.g. + * because of iput(). + */ + might_sleep(); + if (!object) + return; + + /* + * If the @object's refcount cannot drop to zero, we can just decrement + * the refcount without holding a lock. Otherwise, the decrement must + * happen under @object->lock for synchronization with things like + * get_inode_object(). + */ + if (refcount_dec_and_lock(&object->usage, &object->lock)) { + __acquire(&object->lock); + /* + * With @object->lock initially held, remove the reference from + * @object->underobj to @object (if it still exists). + */ + object->underops->release(object); + kfree_rcu(object, rcu_free); + } +} diff --git a/security/landlock/object.h b/security/landlock/object.h new file mode 100644 index 000000000000..3f80674c6c8d --- /dev/null +++ b/security/landlock/object.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Object management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_OBJECT_H +#define _SECURITY_LANDLOCK_OBJECT_H + +#include <linux/compiler_types.h> +#include <linux/refcount.h> +#include <linux/spinlock.h> + +struct landlock_object; + +/** + * struct landlock_object_underops - Operations on an underlying object + */ +struct landlock_object_underops { + /** + * @release: Releases the underlying object (e.g. iput() for an inode). + */ + void (*release)(struct landlock_object *const object) + __releases(object->lock); +}; + +/** + * struct landlock_object - Security blob tied to a kernel object + * + * The goal of this structure is to enable to tie a set of ephemeral access + * rights (pertaining to different domains) to a kernel object (e.g an inode) + * in a safe way. This implies to handle concurrent use and modification. + * + * The lifetime of a &struct landlock_object depends on the rules referring to + * it. + */ +struct landlock_object { + /** + * @usage: This counter is used to tie an object to the rules matching + * it or to keep it alive while adding a new rule. If this counter + * reaches zero, this struct must not be modified, but this counter can + * still be read from within an RCU read-side critical section. When + * adding a new rule to an object with a usage counter of zero, we must + * wait until the pointer to this object is set to NULL (or recycled). + */ + refcount_t usage; + /** + * @lock: Protects against concurrent modifications. This lock must be + * held from the time @usage drops to zero until any weak references + * from @underobj to this object have been cleaned up. + * + * Lock ordering: inode->i_lock nests inside this. + */ + spinlock_t lock; + /** + * @underobj: Used when cleaning up an object and to mark an object as + * tied to its underlying kernel structure. This pointer is protected + * by @lock. Cf. landlock_release_inodes() and release_inode(). + */ + void *underobj; + union { + /** + * @rcu_free: Enables lockless use of @usage, @lock and + * @underobj from within an RCU read-side critical section. + * @rcu_free and @underops are only used by + * landlock_put_object(). + */ + struct rcu_head rcu_free; + /** + * @underops: Enables landlock_put_object() to release the + * underlying object (e.g. inode). + */ + const struct landlock_object_underops *underops; + }; +}; + +struct landlock_object *landlock_create_object( + const struct landlock_object_underops *const underops, + void *const underobj); + +void landlock_put_object(struct landlock_object *const object); + +static inline void landlock_get_object(struct landlock_object *const object) +{ + if (object) + refcount_inc(&object->usage); +} + +#endif /* _SECURITY_LANDLOCK_OBJECT_H */ diff --git a/security/landlock/ptrace.c b/security/landlock/ptrace.c new file mode 100644 index 000000000000..f55b82446de2 --- /dev/null +++ b/security/landlock/ptrace.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Ptrace hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019-2020 ANSSI + */ + +#include <asm/current.h> +#include <linux/cred.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/lsm_hooks.h> +#include <linux/rcupdate.h> +#include <linux/sched.h> + +#include "common.h" +#include "cred.h" +#include "ptrace.h" +#include "ruleset.h" +#include "setup.h" + +/** + * domain_scope_le - Checks domain ordering for scoped ptrace + * + * @parent: Parent domain. + * @child: Potential child of @parent. + * + * Checks if the @parent domain is less or equal to (i.e. an ancestor, which + * means a subset of) the @child domain. + */ +static bool domain_scope_le(const struct landlock_ruleset *const parent, + const struct landlock_ruleset *const child) +{ + const struct landlock_hierarchy *walker; + + if (!parent) + return true; + if (!child) + return false; + for (walker = child->hierarchy; walker; walker = walker->parent) { + if (walker == parent->hierarchy) + /* @parent is in the scoped hierarchy of @child. */ + return true; + } + /* There is no relationship between @parent and @child. */ + return false; +} + +static bool task_is_scoped(const struct task_struct *const parent, + const struct task_struct *const child) +{ + bool is_scoped; + const struct landlock_ruleset *dom_parent, *dom_child; + + rcu_read_lock(); + dom_parent = landlock_get_task_domain(parent); + dom_child = landlock_get_task_domain(child); + is_scoped = domain_scope_le(dom_parent, dom_child); + rcu_read_unlock(); + return is_scoped; +} + +static int task_ptrace(const struct task_struct *const parent, + const struct task_struct *const child) +{ + /* Quick return for non-landlocked tasks. */ + if (!landlocked(parent)) + return 0; + if (task_is_scoped(parent, child)) + return 0; + return -EPERM; +} + +/** + * hook_ptrace_access_check - Determines whether the current process may access + * another + * + * @child: Process to be accessed. + * @mode: Mode of attachment. + * + * If the current task has Landlock rules, then the child must have at least + * the same rules. Else denied. + * + * Determines whether a process may access another, returning 0 if permission + * granted, -errno if denied. + */ +static int hook_ptrace_access_check(struct task_struct *const child, + const unsigned int mode) +{ + return task_ptrace(current, child); +} + +/** + * hook_ptrace_traceme - Determines whether another process may trace the + * current one + * + * @parent: Task proposed to be the tracer. + * + * If the parent has Landlock rules, then the current task must have the same + * or more rules. Else denied. + * + * Determines whether the nominated task is permitted to trace the current + * process, returning 0 if permission is granted, -errno if denied. + */ +static int hook_ptrace_traceme(struct task_struct *const parent) +{ + return task_ptrace(parent, current); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, hook_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, hook_ptrace_traceme), +}; + +__init void landlock_add_ptrace_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/ptrace.h b/security/landlock/ptrace.h new file mode 100644 index 000000000000..265b220ae3bf --- /dev/null +++ b/security/landlock/ptrace.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Ptrace hooks + * + * Copyright © 2017-2019 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_PTRACE_H +#define _SECURITY_LANDLOCK_PTRACE_H + +__init void landlock_add_ptrace_hooks(void); + +#endif /* _SECURITY_LANDLOCK_PTRACE_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c new file mode 100644 index 000000000000..ec72b9262bf3 --- /dev/null +++ b/security/landlock/ruleset.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Ruleset management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/bits.h> +#include <linux/bug.h> +#include <linux/compiler_types.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/lockdep.h> +#include <linux/overflow.h> +#include <linux/rbtree.h> +#include <linux/refcount.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#include "limits.h" +#include "object.h" +#include "ruleset.h" + +static struct landlock_ruleset *create_ruleset(const u32 num_layers) +{ + struct landlock_ruleset *new_ruleset; + + new_ruleset = kzalloc(struct_size(new_ruleset, fs_access_masks, + num_layers), GFP_KERNEL_ACCOUNT); + if (!new_ruleset) + return ERR_PTR(-ENOMEM); + refcount_set(&new_ruleset->usage, 1); + mutex_init(&new_ruleset->lock); + new_ruleset->root = RB_ROOT; + new_ruleset->num_layers = num_layers; + /* + * hierarchy = NULL + * num_rules = 0 + * fs_access_masks[] = 0 + */ + return new_ruleset; +} + +struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask) +{ + struct landlock_ruleset *new_ruleset; + + /* Informs about useless ruleset. */ + if (!fs_access_mask) + return ERR_PTR(-ENOMSG); + new_ruleset = create_ruleset(1); + if (!IS_ERR(new_ruleset)) + new_ruleset->fs_access_masks[0] = fs_access_mask; + return new_ruleset; +} + +static void build_check_rule(void) +{ + const struct landlock_rule rule = { + .num_layers = ~0, + }; + + BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS); +} + +static struct landlock_rule *create_rule( + struct landlock_object *const object, + const struct landlock_layer (*const layers)[], + const u32 num_layers, + const struct landlock_layer *const new_layer) +{ + struct landlock_rule *new_rule; + u32 new_num_layers; + + build_check_rule(); + if (new_layer) { + /* Should already be checked by landlock_merge_ruleset(). */ + if (WARN_ON_ONCE(num_layers >= LANDLOCK_MAX_NUM_LAYERS)) + return ERR_PTR(-E2BIG); + new_num_layers = num_layers + 1; + } else { + new_num_layers = num_layers; + } + new_rule = kzalloc(struct_size(new_rule, layers, new_num_layers), + GFP_KERNEL_ACCOUNT); + if (!new_rule) + return ERR_PTR(-ENOMEM); + RB_CLEAR_NODE(&new_rule->node); + landlock_get_object(object); + new_rule->object = object; + new_rule->num_layers = new_num_layers; + /* Copies the original layer stack. */ + memcpy(new_rule->layers, layers, + flex_array_size(new_rule, layers, num_layers)); + if (new_layer) + /* Adds a copy of @new_layer on the layer stack. */ + new_rule->layers[new_rule->num_layers - 1] = *new_layer; + return new_rule; +} + +static void free_rule(struct landlock_rule *const rule) +{ + might_sleep(); + if (!rule) + return; + landlock_put_object(rule->object); + kfree(rule); +} + +static void build_check_ruleset(void) +{ + const struct landlock_ruleset ruleset = { + .num_rules = ~0, + .num_layers = ~0, + }; + typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; + + BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); + BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); + BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); +} + +/** + * insert_rule - Create and insert a rule in a ruleset + * + * @ruleset: The ruleset to be updated. + * @object: The object to build the new rule with. The underlying kernel + * object must be held by the caller. + * @layers: One or multiple layers to be copied into the new rule. + * @num_layers: The number of @layers entries. + * + * When user space requests to add a new rule to a ruleset, @layers only + * contains one entry and this entry is not assigned to any level. In this + * case, the new rule will extend @ruleset, similarly to a boolean OR between + * access rights. + * + * When merging a ruleset in a domain, or copying a domain, @layers will be + * added to @ruleset as new constraints, similarly to a boolean AND between + * access rights. + */ +static int insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, + const struct landlock_layer (*const layers)[], + size_t num_layers) +{ + struct rb_node **walker_node; + struct rb_node *parent_node = NULL; + struct landlock_rule *new_rule; + + might_sleep(); + lockdep_assert_held(&ruleset->lock); + if (WARN_ON_ONCE(!object || !layers)) + return -ENOENT; + walker_node = &(ruleset->root.rb_node); + while (*walker_node) { + struct landlock_rule *const this = rb_entry(*walker_node, + struct landlock_rule, node); + + if (this->object != object) { + parent_node = *walker_node; + if (this->object < object) + walker_node = &((*walker_node)->rb_right); + else + walker_node = &((*walker_node)->rb_left); + continue; + } + + /* Only a single-level layer should match an existing rule. */ + if (WARN_ON_ONCE(num_layers != 1)) + return -EINVAL; + + /* If there is a matching rule, updates it. */ + if ((*layers)[0].level == 0) { + /* + * Extends access rights when the request comes from + * landlock_add_rule(2), i.e. @ruleset is not a domain. + */ + if (WARN_ON_ONCE(this->num_layers != 1)) + return -EINVAL; + if (WARN_ON_ONCE(this->layers[0].level != 0)) + return -EINVAL; + this->layers[0].access |= (*layers)[0].access; + return 0; + } + + if (WARN_ON_ONCE(this->layers[0].level == 0)) + return -EINVAL; + + /* + * Intersects access rights when it is a merge between a + * ruleset and a domain. + */ + new_rule = create_rule(object, &this->layers, this->num_layers, + &(*layers)[0]); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_replace_node(&this->node, &new_rule->node, &ruleset->root); + free_rule(this); + return 0; + } + + /* There is no match for @object. */ + build_check_ruleset(); + if (ruleset->num_rules >= LANDLOCK_MAX_NUM_RULES) + return -E2BIG; + new_rule = create_rule(object, layers, num_layers, NULL); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_link_node(&new_rule->node, parent_node, walker_node); + rb_insert_color(&new_rule->node, &ruleset->root); + ruleset->num_rules++; + return 0; +} + +static void build_check_layer(void) +{ + const struct landlock_layer layer = { + .level = ~0, + .access = ~0, + }; + + BUILD_BUG_ON(layer.level < LANDLOCK_MAX_NUM_LAYERS); + BUILD_BUG_ON(layer.access < LANDLOCK_MASK_ACCESS_FS); +} + +/* @ruleset must be locked by the caller. */ +int landlock_insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, const u32 access) +{ + struct landlock_layer layers[] = {{ + .access = access, + /* When @level is zero, insert_rule() extends @ruleset. */ + .level = 0, + }}; + + build_check_layer(); + return insert_rule(ruleset, object, &layers, ARRAY_SIZE(layers)); +} + +static inline void get_hierarchy(struct landlock_hierarchy *const hierarchy) +{ + if (hierarchy) + refcount_inc(&hierarchy->usage); +} + +static void put_hierarchy(struct landlock_hierarchy *hierarchy) +{ + while (hierarchy && refcount_dec_and_test(&hierarchy->usage)) { + const struct landlock_hierarchy *const freeme = hierarchy; + + hierarchy = hierarchy->parent; + kfree(freeme); + } +} + +static int merge_ruleset(struct landlock_ruleset *const dst, + struct landlock_ruleset *const src) +{ + struct landlock_rule *walker_rule, *next_rule; + int err = 0; + + might_sleep(); + /* Should already be checked by landlock_merge_ruleset() */ + if (WARN_ON_ONCE(!src)) + return 0; + /* Only merge into a domain. */ + if (WARN_ON_ONCE(!dst || !dst->hierarchy)) + return -EINVAL; + + /* Locks @dst first because we are its only owner. */ + mutex_lock(&dst->lock); + mutex_lock_nested(&src->lock, SINGLE_DEPTH_NESTING); + + /* Stacks the new layer. */ + if (WARN_ON_ONCE(src->num_layers != 1 || dst->num_layers < 1)) { + err = -EINVAL; + goto out_unlock; + } + dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; + + /* Merges the @src tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, + &src->root, node) { + struct landlock_layer layers[] = {{ + .level = dst->num_layers, + }}; + + if (WARN_ON_ONCE(walker_rule->num_layers != 1)) { + err = -EINVAL; + goto out_unlock; + } + if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) { + err = -EINVAL; + goto out_unlock; + } + layers[0].access = walker_rule->layers[0].access; + err = insert_rule(dst, walker_rule->object, &layers, + ARRAY_SIZE(layers)); + if (err) + goto out_unlock; + } + +out_unlock: + mutex_unlock(&src->lock); + mutex_unlock(&dst->lock); + return err; +} + +static int inherit_ruleset(struct landlock_ruleset *const parent, + struct landlock_ruleset *const child) +{ + struct landlock_rule *walker_rule, *next_rule; + int err = 0; + + might_sleep(); + if (!parent) + return 0; + + /* Locks @child first because we are its only owner. */ + mutex_lock(&child->lock); + mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING); + + /* Copies the @parent tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, + &parent->root, node) { + err = insert_rule(child, walker_rule->object, + &walker_rule->layers, walker_rule->num_layers); + if (err) + goto out_unlock; + } + + if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { + err = -EINVAL; + goto out_unlock; + } + /* Copies the parent layer stack and leaves a space for the new layer. */ + memcpy(child->fs_access_masks, parent->fs_access_masks, + flex_array_size(parent, fs_access_masks, parent->num_layers)); + + if (WARN_ON_ONCE(!parent->hierarchy)) { + err = -EINVAL; + goto out_unlock; + } + get_hierarchy(parent->hierarchy); + child->hierarchy->parent = parent->hierarchy; + +out_unlock: + mutex_unlock(&parent->lock); + mutex_unlock(&child->lock); + return err; +} + +static void free_ruleset(struct landlock_ruleset *const ruleset) +{ + struct landlock_rule *freeme, *next; + + might_sleep(); + rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root, + node) + free_rule(freeme); + put_hierarchy(ruleset->hierarchy); + kfree(ruleset); +} + +void landlock_put_ruleset(struct landlock_ruleset *const ruleset) +{ + might_sleep(); + if (ruleset && refcount_dec_and_test(&ruleset->usage)) + free_ruleset(ruleset); +} + +static void free_ruleset_work(struct work_struct *const work) +{ + struct landlock_ruleset *ruleset; + + ruleset = container_of(work, struct landlock_ruleset, work_free); + free_ruleset(ruleset); +} + +void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset) +{ + if (ruleset && refcount_dec_and_test(&ruleset->usage)) { + INIT_WORK(&ruleset->work_free, free_ruleset_work); + schedule_work(&ruleset->work_free); + } +} + +/** + * landlock_merge_ruleset - Merge a ruleset with a domain + * + * @parent: Parent domain. + * @ruleset: New ruleset to be merged. + * + * Returns the intersection of @parent and @ruleset, or returns @parent if + * @ruleset is empty, or returns a duplicate of @ruleset if @parent is empty. + */ +struct landlock_ruleset *landlock_merge_ruleset( + struct landlock_ruleset *const parent, + struct landlock_ruleset *const ruleset) +{ + struct landlock_ruleset *new_dom; + u32 num_layers; + int err; + + might_sleep(); + if (WARN_ON_ONCE(!ruleset || parent == ruleset)) + return ERR_PTR(-EINVAL); + + if (parent) { + if (parent->num_layers >= LANDLOCK_MAX_NUM_LAYERS) + return ERR_PTR(-E2BIG); + num_layers = parent->num_layers + 1; + } else { + num_layers = 1; + } + + /* Creates a new domain... */ + new_dom = create_ruleset(num_layers); + if (IS_ERR(new_dom)) + return new_dom; + new_dom->hierarchy = kzalloc(sizeof(*new_dom->hierarchy), + GFP_KERNEL_ACCOUNT); + if (!new_dom->hierarchy) { + err = -ENOMEM; + goto out_put_dom; + } + refcount_set(&new_dom->hierarchy->usage, 1); + + /* ...as a child of @parent... */ + err = inherit_ruleset(parent, new_dom); + if (err) + goto out_put_dom; + + /* ...and including @ruleset. */ + err = merge_ruleset(new_dom, ruleset); + if (err) + goto out_put_dom; + + return new_dom; + +out_put_dom: + landlock_put_ruleset(new_dom); + return ERR_PTR(err); +} + +/* + * The returned access has the same lifetime as @ruleset. + */ +const struct landlock_rule *landlock_find_rule( + const struct landlock_ruleset *const ruleset, + const struct landlock_object *const object) +{ + const struct rb_node *node; + + if (!object) + return NULL; + node = ruleset->root.rb_node; + while (node) { + struct landlock_rule *this = rb_entry(node, + struct landlock_rule, node); + + if (this->object == object) + return this; + if (this->object < object) + node = node->rb_right; + else + node = node->rb_left; + } + return NULL; +} diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h new file mode 100644 index 000000000000..2d3ed7ec5a0a --- /dev/null +++ b/security/landlock/ruleset.h @@ -0,0 +1,165 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Ruleset management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_RULESET_H +#define _SECURITY_LANDLOCK_RULESET_H + +#include <linux/mutex.h> +#include <linux/rbtree.h> +#include <linux/refcount.h> +#include <linux/workqueue.h> + +#include "object.h" + +/** + * struct landlock_layer - Access rights for a given layer + */ +struct landlock_layer { + /** + * @level: Position of this layer in the layer stack. + */ + u16 level; + /** + * @access: Bitfield of allowed actions on the kernel object. They are + * relative to the object type (e.g. %LANDLOCK_ACTION_FS_READ). + */ + u16 access; +}; + +/** + * struct landlock_rule - Access rights tied to an object + */ +struct landlock_rule { + /** + * @node: Node in the ruleset's red-black tree. + */ + struct rb_node node; + /** + * @object: Pointer to identify a kernel object (e.g. an inode). This + * is used as a key for this ruleset element. This pointer is set once + * and never modified. It always points to an allocated object because + * each rule increments the refcount of its object. + */ + struct landlock_object *object; + /** + * @num_layers: Number of entries in @layers. + */ + u32 num_layers; + /** + * @layers: Stack of layers, from the latest to the newest, implemented + * as a flexible array member (FAM). + */ + struct landlock_layer layers[]; +}; + +/** + * struct landlock_hierarchy - Node in a ruleset hierarchy + */ +struct landlock_hierarchy { + /** + * @parent: Pointer to the parent node, or NULL if it is a root + * Landlock domain. + */ + struct landlock_hierarchy *parent; + /** + * @usage: Number of potential children domains plus their parent + * domain. + */ + refcount_t usage; +}; + +/** + * struct landlock_ruleset - Landlock ruleset + * + * This data structure must contain unique entries, be updatable, and quick to + * match an object. + */ +struct landlock_ruleset { + /** + * @root: Root of a red-black tree containing &struct landlock_rule + * nodes. Once a ruleset is tied to a process (i.e. as a domain), this + * tree is immutable until @usage reaches zero. + */ + struct rb_root root; + /** + * @hierarchy: Enables hierarchy identification even when a parent + * domain vanishes. This is needed for the ptrace protection. + */ + struct landlock_hierarchy *hierarchy; + union { + /** + * @work_free: Enables to free a ruleset within a lockless + * section. This is only used by + * landlock_put_ruleset_deferred() when @usage reaches zero. + * The fields @lock, @usage, @num_rules, @num_layers and + * @fs_access_masks are then unused. + */ + struct work_struct work_free; + struct { + /** + * @lock: Protects against concurrent modifications of + * @root, if @usage is greater than zero. + */ + struct mutex lock; + /** + * @usage: Number of processes (i.e. domains) or file + * descriptors referencing this ruleset. + */ + refcount_t usage; + /** + * @num_rules: Number of non-overlapping (i.e. not for + * the same object) rules in this ruleset. + */ + u32 num_rules; + /** + * @num_layers: Number of layers that are used in this + * ruleset. This enables to check that all the layers + * allow an access request. A value of 0 identifies a + * non-merged ruleset (i.e. not a domain). + */ + u32 num_layers; + /** + * @fs_access_masks: Contains the subset of filesystem + * actions that are restricted by a ruleset. A domain + * saves all layers of merged rulesets in a stack + * (FAM), starting from the first layer to the last + * one. These layers are used when merging rulesets, + * for user space backward compatibility (i.e. + * future-proof), and to properly handle merged + * rulesets without overlapping access rights. These + * layers are set once and never changed for the + * lifetime of the ruleset. + */ + u16 fs_access_masks[]; + }; + }; +}; + +struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask); + +void landlock_put_ruleset(struct landlock_ruleset *const ruleset); +void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); + +int landlock_insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, const u32 access); + +struct landlock_ruleset *landlock_merge_ruleset( + struct landlock_ruleset *const parent, + struct landlock_ruleset *const ruleset); + +const struct landlock_rule *landlock_find_rule( + const struct landlock_ruleset *const ruleset, + const struct landlock_object *const object); + +static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) +{ + if (ruleset) + refcount_inc(&ruleset->usage); +} + +#endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/setup.c b/security/landlock/setup.c new file mode 100644 index 000000000000..f8e8e980454c --- /dev/null +++ b/security/landlock/setup.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Security framework setup + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/init.h> +#include <linux/lsm_hooks.h> + +#include "common.h" +#include "cred.h" +#include "fs.h" +#include "ptrace.h" +#include "setup.h" + +bool landlock_initialized __lsm_ro_after_init = false; + +struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct landlock_cred_security), + .lbs_inode = sizeof(struct landlock_inode_security), + .lbs_superblock = sizeof(struct landlock_superblock_security), +}; + +static int __init landlock_init(void) +{ + landlock_add_cred_hooks(); + landlock_add_ptrace_hooks(); + landlock_add_fs_hooks(); + landlock_initialized = true; + pr_info("Up and running.\n"); + return 0; +} + +DEFINE_LSM(LANDLOCK_NAME) = { + .name = LANDLOCK_NAME, + .init = landlock_init, + .blobs = &landlock_blob_sizes, +}; diff --git a/security/landlock/setup.h b/security/landlock/setup.h new file mode 100644 index 000000000000..1daffab1ab4b --- /dev/null +++ b/security/landlock/setup.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Security framework setup + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_SETUP_H +#define _SECURITY_LANDLOCK_SETUP_H + +#include <linux/lsm_hooks.h> + +extern bool landlock_initialized; + +extern struct lsm_blob_sizes landlock_blob_sizes; + +#endif /* _SECURITY_LANDLOCK_SETUP_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c new file mode 100644 index 000000000000..32396962f04d --- /dev/null +++ b/security/landlock/syscalls.c @@ -0,0 +1,451 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - System call implementations and user space interfaces + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <asm/current.h> +#include <linux/anon_inodes.h> +#include <linux/build_bug.h> +#include <linux/capability.h> +#include <linux/compiler_types.h> +#include <linux/dcache.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/limits.h> +#include <linux/mount.h> +#include <linux/path.h> +#include <linux/sched.h> +#include <linux/security.h> +#include <linux/stddef.h> +#include <linux/syscalls.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <uapi/linux/landlock.h> + +#include "cred.h" +#include "fs.h" +#include "limits.h" +#include "ruleset.h" +#include "setup.h" + +/** + * copy_min_struct_from_user - Safe future-proof argument copying + * + * Extend copy_struct_from_user() to check for consistent user buffer. + * + * @dst: Kernel space pointer or NULL. + * @ksize: Actual size of the data pointed to by @dst. + * @ksize_min: Minimal required size to be copied. + * @src: User space pointer or NULL. + * @usize: (Alleged) size of the data pointed to by @src. + */ +static __always_inline int copy_min_struct_from_user(void *const dst, + const size_t ksize, const size_t ksize_min, + const void __user *const src, const size_t usize) +{ + /* Checks buffer inconsistencies. */ + BUILD_BUG_ON(!dst); + if (!src) + return -EFAULT; + + /* Checks size ranges. */ + BUILD_BUG_ON(ksize <= 0); + BUILD_BUG_ON(ksize < ksize_min); + if (usize < ksize_min) + return -EINVAL; + if (usize > PAGE_SIZE) + return -E2BIG; + + /* Copies user buffer and fills with zeros. */ + return copy_struct_from_user(dst, ksize, src, usize); +} + +/* + * This function only contains arithmetic operations with constants, leading to + * BUILD_BUG_ON(). The related code is evaluated and checked at build time, + * but it is then ignored thanks to compiler optimizations. + */ +static void build_check_abi(void) +{ + struct landlock_ruleset_attr ruleset_attr; + struct landlock_path_beneath_attr path_beneath_attr; + size_t ruleset_size, path_beneath_size; + + /* + * For each user space ABI structures, first checks that there is no + * hole in them, then checks that all architectures have the same + * struct size. + */ + ruleset_size = sizeof(ruleset_attr.handled_access_fs); + BUILD_BUG_ON(sizeof(ruleset_attr) != ruleset_size); + BUILD_BUG_ON(sizeof(ruleset_attr) != 8); + + path_beneath_size = sizeof(path_beneath_attr.allowed_access); + path_beneath_size += sizeof(path_beneath_attr.parent_fd); + BUILD_BUG_ON(sizeof(path_beneath_attr) != path_beneath_size); + BUILD_BUG_ON(sizeof(path_beneath_attr) != 12); +} + +/* Ruleset handling */ + +static int fop_ruleset_release(struct inode *const inode, + struct file *const filp) +{ + struct landlock_ruleset *ruleset = filp->private_data; + + landlock_put_ruleset(ruleset); + return 0; +} + +static ssize_t fop_dummy_read(struct file *const filp, char __user *const buf, + const size_t size, loff_t *const ppos) +{ + /* Dummy handler to enable FMODE_CAN_READ. */ + return -EINVAL; +} + +static ssize_t fop_dummy_write(struct file *const filp, + const char __user *const buf, const size_t size, + loff_t *const ppos) +{ + /* Dummy handler to enable FMODE_CAN_WRITE. */ + return -EINVAL; +} + +/* + * A ruleset file descriptor enables to build a ruleset by adding (i.e. + * writing) rule after rule, without relying on the task's context. This + * reentrant design is also used in a read way to enforce the ruleset on the + * current task. + */ +static const struct file_operations ruleset_fops = { + .release = fop_ruleset_release, + .read = fop_dummy_read, + .write = fop_dummy_write, +}; + +#define LANDLOCK_ABI_VERSION 1 + +/** + * sys_landlock_create_ruleset - Create a new ruleset + * + * @attr: Pointer to a &struct landlock_ruleset_attr identifying the scope of + * the new ruleset. + * @size: Size of the pointed &struct landlock_ruleset_attr (needed for + * backward and forward compatibility). + * @flags: Supported value: %LANDLOCK_CREATE_RULESET_VERSION. + * + * This system call enables to create a new Landlock ruleset, and returns the + * related file descriptor on success. + * + * If @flags is %LANDLOCK_CREATE_RULESET_VERSION and @attr is NULL and @size is + * 0, then the returned value is the highest supported Landlock ABI version + * (starting at 1). + * + * Possible returned errors are: + * + * - EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - EINVAL: unknown @flags, or unknown access, or too small @size; + * - E2BIG or EFAULT: @attr or @size inconsistencies; + * - ENOMSG: empty &landlock_ruleset_attr.handled_access_fs. + */ +SYSCALL_DEFINE3(landlock_create_ruleset, + const struct landlock_ruleset_attr __user *const, attr, + const size_t, size, const __u32, flags) +{ + struct landlock_ruleset_attr ruleset_attr; + struct landlock_ruleset *ruleset; + int err, ruleset_fd; + + /* Build-time checks. */ + build_check_abi(); + + if (!landlock_initialized) + return -EOPNOTSUPP; + + if (flags) { + if ((flags == LANDLOCK_CREATE_RULESET_VERSION) + && !attr && !size) + return LANDLOCK_ABI_VERSION; + return -EINVAL; + } + + /* Copies raw user space buffer. */ + err = copy_min_struct_from_user(&ruleset_attr, sizeof(ruleset_attr), + offsetofend(typeof(ruleset_attr), handled_access_fs), + attr, size); + if (err) + return err; + + /* Checks content (and 32-bits cast). */ + if ((ruleset_attr.handled_access_fs | LANDLOCK_MASK_ACCESS_FS) != + LANDLOCK_MASK_ACCESS_FS) + return -EINVAL; + + /* Checks arguments and transforms to kernel struct. */ + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + /* Creates anonymous FD referring to the ruleset. */ + ruleset_fd = anon_inode_getfd("landlock-ruleset", &ruleset_fops, + ruleset, O_RDWR | O_CLOEXEC); + if (ruleset_fd < 0) + landlock_put_ruleset(ruleset); + return ruleset_fd; +} + +/* + * Returns an owned ruleset from a FD. It is thus needed to call + * landlock_put_ruleset() on the return value. + */ +static struct landlock_ruleset *get_ruleset_from_fd(const int fd, + const fmode_t mode) +{ + struct fd ruleset_f; + struct landlock_ruleset *ruleset; + + ruleset_f = fdget(fd); + if (!ruleset_f.file) + return ERR_PTR(-EBADF); + + /* Checks FD type and access right. */ + if (ruleset_f.file->f_op != &ruleset_fops) { + ruleset = ERR_PTR(-EBADFD); + goto out_fdput; + } + if (!(ruleset_f.file->f_mode & mode)) { + ruleset = ERR_PTR(-EPERM); + goto out_fdput; + } + ruleset = ruleset_f.file->private_data; + if (WARN_ON_ONCE(ruleset->num_layers != 1)) { + ruleset = ERR_PTR(-EINVAL); + goto out_fdput; + } + landlock_get_ruleset(ruleset); + +out_fdput: + fdput(ruleset_f); + return ruleset; +} + +/* Path handling */ + +/* + * @path: Must call put_path(@path) after the call if it succeeded. + */ +static int get_path_from_fd(const s32 fd, struct path *const path) +{ + struct fd f; + int err = 0; + + BUILD_BUG_ON(!__same_type(fd, + ((struct landlock_path_beneath_attr *)NULL)->parent_fd)); + + /* Handles O_PATH. */ + f = fdget_raw(fd); + if (!f.file) + return -EBADF; + /* + * Forbids ruleset FDs, internal filesystems (e.g. nsfs), including + * pseudo filesystems that will never be mountable (e.g. sockfs, + * pipefs). + */ + if ((f.file->f_op == &ruleset_fops) || + (f.file->f_path.mnt->mnt_flags & MNT_INTERNAL) || + (f.file->f_path.dentry->d_sb->s_flags & SB_NOUSER) || + d_is_negative(f.file->f_path.dentry) || + IS_PRIVATE(d_backing_inode(f.file->f_path.dentry))) { + err = -EBADFD; + goto out_fdput; + } + *path = f.file->f_path; + path_get(path); + +out_fdput: + fdput(f); + return err; +} + +/** + * sys_landlock_add_rule - Add a new rule to a ruleset + * + * @ruleset_fd: File descriptor tied to the ruleset that should be extended + * with the new rule. + * @rule_type: Identify the structure type pointed to by @rule_attr (only + * LANDLOCK_RULE_PATH_BENEATH for now). + * @rule_attr: Pointer to a rule (only of type &struct + * landlock_path_beneath_attr for now). + * @flags: Must be 0. + * + * This system call enables to define a new rule and add it to an existing + * ruleset. + * + * Possible returned errors are: + * + * - EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - EINVAL: @flags is not 0, or inconsistent access in the rule (i.e. + * &landlock_path_beneath_attr.allowed_access is not a subset of the rule's + * accesses); + * - ENOMSG: Empty accesses (e.g. &landlock_path_beneath_attr.allowed_access); + * - EBADF: @ruleset_fd is not a file descriptor for the current thread, or a + * member of @rule_attr is not a file descriptor as expected; + * - EBADFD: @ruleset_fd is not a ruleset file descriptor, or a member of + * @rule_attr is not the expected file descriptor type (e.g. file open + * without O_PATH); + * - EPERM: @ruleset_fd has no write access to the underlying ruleset; + * - EFAULT: @rule_attr inconsistency. + */ +SYSCALL_DEFINE4(landlock_add_rule, + const int, ruleset_fd, const enum landlock_rule_type, rule_type, + const void __user *const, rule_attr, const __u32, flags) +{ + struct landlock_path_beneath_attr path_beneath_attr; + struct path path; + struct landlock_ruleset *ruleset; + int res, err; + + if (!landlock_initialized) + return -EOPNOTSUPP; + + /* No flag for now. */ + if (flags) + return -EINVAL; + + if (rule_type != LANDLOCK_RULE_PATH_BENEATH) + return -EINVAL; + + /* Copies raw user space buffer, only one type for now. */ + res = copy_from_user(&path_beneath_attr, rule_attr, + sizeof(path_beneath_attr)); + if (res) + return -EFAULT; + + /* Gets and checks the ruleset. */ + ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_WRITE); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + /* + * Informs about useless rule: empty allowed_access (i.e. deny rules) + * are ignored in path walks. + */ + if (!path_beneath_attr.allowed_access) { + err = -ENOMSG; + goto out_put_ruleset; + } + /* + * Checks that allowed_access matches the @ruleset constraints + * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). + */ + if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != + ruleset->fs_access_masks[0]) { + err = -EINVAL; + goto out_put_ruleset; + } + + /* Gets and checks the new rule. */ + err = get_path_from_fd(path_beneath_attr.parent_fd, &path); + if (err) + goto out_put_ruleset; + + /* Imports the new rule. */ + err = landlock_append_fs_rule(ruleset, &path, + path_beneath_attr.allowed_access); + path_put(&path); + +out_put_ruleset: + landlock_put_ruleset(ruleset); + return err; +} + +/* Enforcement */ + +/** + * sys_landlock_restrict_self - Enforce a ruleset on the calling thread + * + * @ruleset_fd: File descriptor tied to the ruleset to merge with the target. + * @flags: Must be 0. + * + * This system call enables to enforce a Landlock ruleset on the current + * thread. Enforcing a ruleset requires that the task has CAP_SYS_ADMIN in its + * namespace or is running with no_new_privs. This avoids scenarios where + * unprivileged tasks can affect the behavior of privileged children. + * + * Possible returned errors are: + * + * - EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - EINVAL: @flags is not 0. + * - EBADF: @ruleset_fd is not a file descriptor for the current thread; + * - EBADFD: @ruleset_fd is not a ruleset file descriptor; + * - EPERM: @ruleset_fd has no read access to the underlying ruleset, or the + * current thread is not running with no_new_privs, or it doesn't have + * CAP_SYS_ADMIN in its namespace. + * - E2BIG: The maximum number of stacked rulesets is reached for the current + * thread. + */ +SYSCALL_DEFINE2(landlock_restrict_self, + const int, ruleset_fd, const __u32, flags) +{ + struct landlock_ruleset *new_dom, *ruleset; + struct cred *new_cred; + struct landlock_cred_security *new_llcred; + int err; + + if (!landlock_initialized) + return -EOPNOTSUPP; + + /* No flag for now. */ + if (flags) + return -EINVAL; + + /* + * Similar checks as for seccomp(2), except that an -EPERM may be + * returned. + */ + if (!task_no_new_privs(current) && + !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) + return -EPERM; + + /* Gets and checks the ruleset. */ + ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_READ); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + /* Prepares new credentials. */ + new_cred = prepare_creds(); + if (!new_cred) { + err = -ENOMEM; + goto out_put_ruleset; + } + new_llcred = landlock_cred(new_cred); + + /* + * There is no possible race condition while copying and manipulating + * the current credentials because they are dedicated per thread. + */ + new_dom = landlock_merge_ruleset(new_llcred->domain, ruleset); + if (IS_ERR(new_dom)) { + err = PTR_ERR(new_dom); + goto out_put_creds; + } + + /* Replaces the old (prepared) domain. */ + landlock_put_ruleset(new_llcred->domain); + new_llcred->domain = new_dom; + + landlock_put_ruleset(ruleset); + return commit_creds(new_cred); + +out_put_creds: + abort_creds(new_cred); + +out_put_ruleset: + landlock_put_ruleset(ruleset); + return err; +} diff --git a/security/security.c b/security/security.c index 5ac96b16f8fa..b38155b2de83 100644 --- a/security/security.c +++ b/security/security.c @@ -203,6 +203,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); + lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task); } @@ -333,12 +334,13 @@ static void __init ordered_lsm_init(void) for (lsm = ordered_lsms; *lsm; lsm++) prepare_lsm(*lsm); - init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); - init_debug("file blob size = %d\n", blob_sizes.lbs_file); - init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); - init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); - init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); - init_debug("task blob size = %d\n", blob_sizes.lbs_task); + init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); + init_debug("file blob size = %d\n", blob_sizes.lbs_file); + init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); + init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); + init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); + init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); + init_debug("task blob size = %d\n", blob_sizes.lbs_task); /* * Create any kmem_caches needed for blobs @@ -670,6 +672,27 @@ static void __init lsm_early_task(struct task_struct *task) panic("%s: Early task alloc failed.\n", __func__); } +/** + * lsm_superblock_alloc - allocate a composite superblock blob + * @sb: the superblock that needs a blob + * + * Allocate the superblock blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_superblock_alloc(struct super_block *sb) +{ + if (blob_sizes.lbs_superblock == 0) { + sb->s_security = NULL; + return 0; + } + + sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL); + if (sb->s_security == NULL) + return -ENOMEM; + return 0; +} + /* * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and * can be accessed with: @@ -867,12 +890,26 @@ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter * int security_sb_alloc(struct super_block *sb) { - return call_int_hook(sb_alloc_security, 0, sb); + int rc = lsm_superblock_alloc(sb); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sb_alloc_security, 0, sb); + if (unlikely(rc)) + security_sb_free(sb); + return rc; +} + +void security_sb_delete(struct super_block *sb) +{ + call_void_hook(sb_delete, sb); } void security_sb_free(struct super_block *sb) { call_void_hook(sb_free_security, sb); + kfree(sb->s_security); + sb->s_security = NULL; } void security_free_mnt_opts(void **mnt_opts) @@ -890,6 +927,13 @@ int security_sb_eat_lsm_opts(char *options, void **mnt_opts) } EXPORT_SYMBOL(security_sb_eat_lsm_opts); +int security_sb_mnt_opts_compat(struct super_block *sb, + void *mnt_opts) +{ + return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts); +} +EXPORT_SYMBOL(security_sb_mnt_opts_compat); + int security_sb_remount(struct super_block *sb, void *mnt_opts) { @@ -1762,12 +1806,19 @@ int security_task_getsid(struct task_struct *p) return call_int_hook(task_getsid, 0, p); } -void security_task_getsecid(struct task_struct *p, u32 *secid) +void security_task_getsecid_subj(struct task_struct *p, u32 *secid) +{ + *secid = 0; + call_void_hook(task_getsecid_subj, p, secid); +} +EXPORT_SYMBOL(security_task_getsecid_subj); + +void security_task_getsecid_obj(struct task_struct *p, u32 *secid) { *secid = 0; - call_void_hook(task_getsecid, p, secid); + call_void_hook(task_getsecid_obj, p, secid); } -EXPORT_SYMBOL(security_task_getsecid); +EXPORT_SYMBOL(security_task_getsecid_obj); int security_task_setnice(struct task_struct *p, int nice) { diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ddd097790d47..eaea837d89d1 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -230,9 +230,22 @@ static inline u32 cred_sid(const struct cred *cred) } /* + * get the subjective security ID of a task + */ +static inline u32 task_sid_subj(const struct task_struct *task) +{ + u32 sid; + + rcu_read_lock(); + sid = cred_sid(rcu_dereference(task->cred)); + rcu_read_unlock(); + return sid; +} + +/* * get the objective security ID of a task */ -static inline u32 task_sid(const struct task_struct *task) +static inline u32 task_sid_obj(const struct task_struct *task) { u32 sid; @@ -242,6 +255,29 @@ static inline u32 task_sid(const struct task_struct *task) return sid; } +/* + * get the security ID of a task for use with binder + */ +static inline u32 task_sid_binder(const struct task_struct *task) +{ + /* + * In many case where this function is used we should be using the + * task's subjective SID, but we can't reliably access the subjective + * creds of a task other than our own so we must use the objective + * creds/SID, which are safe to access. The downside is that if a task + * is temporarily overriding it's creds it will not be reflected here; + * however, it isn't clear that binder would handle that case well + * anyway. + * + * If this ever changes and we can safely reference the subjective + * creds/SID of another task, this function will make it easier to + * identify the various places where we make use of the task SIDs in + * the binder code. It is also likely that we will need to adjust + * the main drivers/android binder code as well. + */ + return task_sid_obj(task); +} + static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); /* @@ -322,7 +358,7 @@ static void inode_free_security(struct inode *inode) if (!isec) return; - sbsec = inode->i_sb->s_security; + sbsec = selinux_superblock(inode->i_sb); /* * As not all inode security structures are in a list, we check for * empty list outside of the lock to make sure that we won't waste @@ -340,13 +376,6 @@ static void inode_free_security(struct inode *inode) } } -static void superblock_free_security(struct super_block *sb) -{ - struct superblock_security_struct *sbsec = sb->s_security; - sb->s_security = NULL; - kfree(sbsec); -} - struct selinux_mnt_opts { const char *fscontext, *context, *rootcontext, *defcontext; }; @@ -458,7 +487,7 @@ static int selinux_is_genfs_special_handling(struct super_block *sb) static int selinux_is_sblabel_mnt(struct super_block *sb) { - struct superblock_security_struct *sbsec = sb->s_security; + struct superblock_security_struct *sbsec = selinux_superblock(sb); /* * IMPORTANT: Double-check logic in this function when adding a new @@ -535,7 +564,7 @@ fallback: static int sb_finish_set_opts(struct super_block *sb) { - struct superblock_security_struct *sbsec = sb->s_security; + struct superblock_security_struct *sbsec = selinux_superblock(sb); struct dentry *root = sb->s_root; struct inode *root_inode = d_backing_inode(root); int rc = 0; @@ -626,7 +655,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, unsigned long *set_kern_flags) { const struct cred *cred = current_cred(); - struct superblock_security_struct *sbsec = sb->s_security; + struct superblock_security_struct *sbsec = selinux_superblock(sb); struct dentry *root = sb->s_root; struct selinux_mnt_opts *opts = mnt_opts; struct inode_security_struct *root_isec; @@ -760,7 +789,8 @@ static int selinux_set_mnt_opts(struct super_block *sb, if (sb->s_user_ns != &init_user_ns && strcmp(sb->s_type->name, "tmpfs") && strcmp(sb->s_type->name, "ramfs") && - strcmp(sb->s_type->name, "devpts")) { + strcmp(sb->s_type->name, "devpts") && + strcmp(sb->s_type->name, "overlay")) { if (context_sid || fscontext_sid || rootcontext_sid || defcontext_sid) { rc = -EACCES; @@ -863,8 +893,8 @@ out_double_mount: static int selinux_cmp_sb_context(const struct super_block *oldsb, const struct super_block *newsb) { - struct superblock_security_struct *old = oldsb->s_security; - struct superblock_security_struct *new = newsb->s_security; + struct superblock_security_struct *old = selinux_superblock(oldsb); + struct superblock_security_struct *new = selinux_superblock(newsb); char oldflags = old->flags & SE_MNTMASK; char newflags = new->flags & SE_MNTMASK; @@ -896,8 +926,9 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, unsigned long *set_kern_flags) { int rc = 0; - const struct superblock_security_struct *oldsbsec = oldsb->s_security; - struct superblock_security_struct *newsbsec = newsb->s_security; + const struct superblock_security_struct *oldsbsec = + selinux_superblock(oldsb); + struct superblock_security_struct *newsbsec = selinux_superblock(newsb); int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); int set_context = (oldsbsec->flags & CONTEXT_MNT); @@ -1076,7 +1107,7 @@ static int show_sid(struct seq_file *m, u32 sid) static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) { - struct superblock_security_struct *sbsec = sb->s_security; + struct superblock_security_struct *sbsec = selinux_superblock(sb); int rc; if (!(sbsec->flags & SE_SBINITIALIZED)) @@ -1427,7 +1458,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent if (isec->sclass == SECCLASS_FILE) isec->sclass = inode_mode_to_security_class(inode->i_mode); - sbsec = inode->i_sb->s_security; + sbsec = selinux_superblock(inode->i_sb); if (!(sbsec->flags & SE_SBINITIALIZED)) { /* Defer initialization until selinux_complete_init, after the initial policy is loaded and the security @@ -1778,7 +1809,8 @@ selinux_determine_inode_label(const struct task_security_struct *tsec, const struct qstr *name, u16 tclass, u32 *_new_isid) { - const struct superblock_security_struct *sbsec = dir->i_sb->s_security; + const struct superblock_security_struct *sbsec = + selinux_superblock(dir->i_sb); if ((sbsec->flags & SE_SBINITIALIZED) && (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { @@ -1809,7 +1841,7 @@ static int may_create(struct inode *dir, int rc; dsec = inode_security(dir); - sbsec = dir->i_sb->s_security; + sbsec = selinux_superblock(dir->i_sb); sid = tsec->sid; @@ -1958,7 +1990,7 @@ static int superblock_has_perm(const struct cred *cred, struct superblock_security_struct *sbsec; u32 sid = cred_sid(cred); - sbsec = sb->s_security; + sbsec = selinux_superblock(sb); return avc_has_perm(&selinux_state, sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); } @@ -2034,11 +2066,8 @@ static inline u32 open_file_to_av(struct file *file) static int selinux_binder_set_context_mgr(struct task_struct *mgr) { - u32 mysid = current_sid(); - u32 mgrsid = task_sid(mgr); - return avc_has_perm(&selinux_state, - mysid, mgrsid, SECCLASS_BINDER, + current_sid(), task_sid_binder(mgr), SECCLASS_BINDER, BINDER__SET_CONTEXT_MGR, NULL); } @@ -2046,8 +2075,7 @@ static int selinux_binder_transaction(struct task_struct *from, struct task_struct *to) { u32 mysid = current_sid(); - u32 fromsid = task_sid(from); - u32 tosid = task_sid(to); + u32 fromsid = task_sid_binder(from); int rc; if (mysid != fromsid) { @@ -2058,19 +2086,16 @@ static int selinux_binder_transaction(struct task_struct *from, return rc; } - return avc_has_perm(&selinux_state, - fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, - NULL); + return avc_has_perm(&selinux_state, fromsid, task_sid_binder(to), + SECCLASS_BINDER, BINDER__CALL, NULL); } static int selinux_binder_transfer_binder(struct task_struct *from, struct task_struct *to) { - u32 fromsid = task_sid(from); - u32 tosid = task_sid(to); - return avc_has_perm(&selinux_state, - fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, + task_sid_binder(from), task_sid_binder(to), + SECCLASS_BINDER, BINDER__TRANSFER, NULL); } @@ -2078,7 +2103,7 @@ static int selinux_binder_transfer_file(struct task_struct *from, struct task_struct *to, struct file *file) { - u32 sid = task_sid(to); + u32 sid = task_sid_binder(to); struct file_security_struct *fsec = selinux_file(file); struct dentry *dentry = file->f_path.dentry; struct inode_security_struct *isec; @@ -2114,10 +2139,10 @@ static int selinux_binder_transfer_file(struct task_struct *from, } static int selinux_ptrace_access_check(struct task_struct *child, - unsigned int mode) + unsigned int mode) { u32 sid = current_sid(); - u32 csid = task_sid(child); + u32 csid = task_sid_obj(child); if (mode & PTRACE_MODE_READ) return avc_has_perm(&selinux_state, @@ -2130,15 +2155,15 @@ static int selinux_ptrace_access_check(struct task_struct *child, static int selinux_ptrace_traceme(struct task_struct *parent) { return avc_has_perm(&selinux_state, - task_sid(parent), current_sid(), SECCLASS_PROCESS, - PROCESS__PTRACE, NULL); + task_sid_subj(parent), task_sid_obj(current), + SECCLASS_PROCESS, PROCESS__PTRACE, NULL); } static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(target), SECCLASS_PROCESS, + current_sid(), task_sid_obj(target), SECCLASS_PROCESS, PROCESS__GETCAP, NULL); } @@ -2263,7 +2288,7 @@ static u32 ptrace_parent_sid(void) rcu_read_lock(); tracer = ptrace_parent(current); if (tracer) - sid = task_sid(tracer); + sid = task_sid_obj(tracer); rcu_read_unlock(); return sid; @@ -2587,11 +2612,7 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm) static int selinux_sb_alloc_security(struct super_block *sb) { - struct superblock_security_struct *sbsec; - - sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); - if (!sbsec) - return -ENOMEM; + struct superblock_security_struct *sbsec = selinux_superblock(sb); mutex_init(&sbsec->lock); INIT_LIST_HEAD(&sbsec->isec_head); @@ -2599,16 +2620,10 @@ static int selinux_sb_alloc_security(struct super_block *sb) sbsec->sid = SECINITSID_UNLABELED; sbsec->def_sid = SECINITSID_FILE; sbsec->mntpoint_sid = SECINITSID_UNLABELED; - sb->s_security = sbsec; return 0; } -static void selinux_sb_free_security(struct super_block *sb) -{ - superblock_free_security(sb); -} - static inline int opt_len(const char *s) { bool open_quote = false; @@ -2684,13 +2699,68 @@ free_opt: return rc; } -static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) +static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts) { struct selinux_mnt_opts *opts = mnt_opts; struct superblock_security_struct *sbsec = sb->s_security; u32 sid; int rc; + /* + * Superblock not initialized (i.e. no options) - reject if any + * options specified, otherwise accept. + */ + if (!(sbsec->flags & SE_SBINITIALIZED)) + return opts ? 1 : 0; + + /* + * Superblock initialized and no options specified - reject if + * superblock has any options set, otherwise accept. + */ + if (!opts) + return (sbsec->flags & SE_MNTMASK) ? 1 : 0; + + if (opts->fscontext) { + rc = parse_sid(sb, opts->fscontext, &sid); + if (rc) + return 1; + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) + return 1; + } + if (opts->context) { + rc = parse_sid(sb, opts->context, &sid); + if (rc) + return 1; + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) + return 1; + } + if (opts->rootcontext) { + struct inode_security_struct *root_isec; + + root_isec = backing_inode_security(sb->s_root); + rc = parse_sid(sb, opts->rootcontext, &sid); + if (rc) + return 1; + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) + return 1; + } + if (opts->defcontext) { + rc = parse_sid(sb, opts->defcontext, &sid); + if (rc) + return 1; + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) + return 1; + } + return 0; +} + +static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) +{ + struct selinux_mnt_opts *opts = mnt_opts; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + u32 sid; + int rc; + if (!(sbsec->flags & SE_SBINITIALIZED)) return 0; @@ -2925,7 +2995,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, int rc; char *context; - sbsec = dir->i_sb->s_security; + sbsec = selinux_superblock(dir->i_sb); newsid = tsec->create_sid; @@ -3227,7 +3297,7 @@ static int selinux_inode_setxattr(struct user_namespace *mnt_userns, if (!selinux_initialized(&selinux_state)) return (inode_owner_or_capable(mnt_userns, inode) ? 0 : -EPERM); - sbsec = inode->i_sb->s_security; + sbsec = selinux_superblock(inode->i_sb); if (!(sbsec->flags & SBLABEL_MNT)) return -EOPNOTSUPP; @@ -3472,13 +3542,14 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) { struct inode_security_struct *isec = inode_security_novalidate(inode); - struct superblock_security_struct *sbsec = inode->i_sb->s_security; + struct superblock_security_struct *sbsec; u32 newsid; int rc; if (strcmp(name, XATTR_SELINUX_SUFFIX)) return -EOPNOTSUPP; + sbsec = selinux_superblock(inode->i_sb); if (!(sbsec->flags & SBLABEL_MNT)) return -EOPNOTSUPP; @@ -3920,7 +3991,7 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int signum) { struct file *file; - u32 sid = task_sid(tsk); + u32 sid = task_sid_obj(tsk); u32 perm; struct file_security_struct *fsec; @@ -4139,47 +4210,52 @@ static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents) static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETPGID, NULL); } static int selinux_task_getpgid(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__GETPGID, NULL); } static int selinux_task_getsid(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__GETSESSION, NULL); } -static void selinux_task_getsecid(struct task_struct *p, u32 *secid) +static void selinux_task_getsecid_subj(struct task_struct *p, u32 *secid) +{ + *secid = task_sid_subj(p); +} + +static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid) { - *secid = task_sid(p); + *secid = task_sid_obj(p); } static int selinux_task_setnice(struct task_struct *p, int nice) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETSCHED, NULL); } static int selinux_task_setioprio(struct task_struct *p, int ioprio) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETSCHED, NULL); } static int selinux_task_getioprio(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__GETSCHED, NULL); } @@ -4210,7 +4286,7 @@ static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, upon context transitions. See selinux_bprm_committing_creds. */ if (old_rlim->rlim_max != new_rlim->rlim_max) return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL); return 0; @@ -4219,21 +4295,21 @@ static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, static int selinux_task_setscheduler(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETSCHED, NULL); } static int selinux_task_getscheduler(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__GETSCHED, NULL); } static int selinux_task_movememory(struct task_struct *p) { return avc_has_perm(&selinux_state, - current_sid(), task_sid(p), SECCLASS_PROCESS, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, PROCESS__SETSCHED, NULL); } @@ -4252,14 +4328,14 @@ static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info, else secid = cred_sid(cred); return avc_has_perm(&selinux_state, - secid, task_sid(p), SECCLASS_PROCESS, perm, NULL); + secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL); } static void selinux_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_security_struct *isec = selinux_inode(inode); - u32 sid = task_sid(p); + u32 sid = task_sid_obj(p); spin_lock(&isec->lock); isec->sclass = inode_mode_to_security_class(inode->i_mode); @@ -6152,7 +6228,7 @@ static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *m struct ipc_security_struct *isec; struct msg_security_struct *msec; struct common_audit_data ad; - u32 sid = task_sid(target); + u32 sid = task_sid_subj(target); int rc; isec = selinux_ipc(msq); @@ -6975,6 +7051,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = { .lbs_inode = sizeof(struct inode_security_struct), .lbs_ipc = sizeof(struct ipc_security_struct), .lbs_msg_msg = sizeof(struct msg_security_struct), + .lbs_superblock = sizeof(struct superblock_security_struct), }; #ifdef CONFIG_PERF_EVENTS @@ -7075,8 +7152,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), - LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security), LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts), + LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat), LSM_HOOK_INIT(sb_remount, selinux_sb_remount), LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount), LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options), @@ -7148,7 +7225,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid), LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid), LSM_HOOK_INIT(task_getsid, selinux_task_getsid), - LSM_HOOK_INIT(task_getsecid, selinux_task_getsecid), + LSM_HOOK_INIT(task_getsecid_subj, selinux_task_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj), LSM_HOOK_INIT(task_setnice, selinux_task_setnice), LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio), LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio), diff --git a/security/selinux/ima.c b/security/selinux/ima.c index 03715893ff97..34d421861bfc 100644 --- a/security/selinux/ima.c +++ b/security/selinux/ima.c @@ -13,18 +13,83 @@ #include "ima.h" /* - * selinux_ima_measure_state - Measure hash of the SELinux policy + * selinux_ima_collect_state - Read selinux configuration settings * - * @state: selinux state struct + * @state: selinux_state * - * NOTE: This function must be called with policy_mutex held. + * On success returns the configuration settings string. + * On error, returns NULL. */ -void selinux_ima_measure_state(struct selinux_state *state) +static char *selinux_ima_collect_state(struct selinux_state *state) { + const char *on = "=1;", *off = "=0;"; + char *buf; + int buf_len, len, i, rc; + + buf_len = strlen("initialized=0;enforcing=0;checkreqprot=0;") + 1; + + len = strlen(on); + for (i = 0; i < __POLICYDB_CAPABILITY_MAX; i++) + buf_len += strlen(selinux_policycap_names[i]) + len; + + buf = kzalloc(buf_len, GFP_KERNEL); + if (!buf) + return NULL; + + rc = strscpy(buf, "initialized", buf_len); + WARN_ON(rc < 0); + + rc = strlcat(buf, selinux_initialized(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, "enforcing", buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, enforcing_enabled(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, "checkreqprot", buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, checkreqprot_get(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + for (i = 0; i < __POLICYDB_CAPABILITY_MAX; i++) { + rc = strlcat(buf, selinux_policycap_names[i], buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, state->policycap[i] ? on : off, buf_len); + WARN_ON(rc >= buf_len); + } + + return buf; +} + +/* + * selinux_ima_measure_state_locked - Measure SELinux state and hash of policy + * + * @state: selinux state struct + */ +void selinux_ima_measure_state_locked(struct selinux_state *state) +{ + char *state_str = NULL; void *policy = NULL; size_t policy_len; int rc = 0; + WARN_ON(!mutex_is_locked(&state->policy_mutex)); + + state_str = selinux_ima_collect_state(state); + if (!state_str) { + pr_err("SELinux: %s: failed to read state.\n", __func__); + return; + } + + ima_measure_critical_data("selinux", "selinux-state", + state_str, strlen(state_str), false); + + kfree(state_str); + /* * Measure SELinux policy only after initialization is completed. */ @@ -42,3 +107,17 @@ void selinux_ima_measure_state(struct selinux_state *state) vfree(policy); } + +/* + * selinux_ima_measure_state - Measure SELinux state and hash of policy + * + * @state: selinux state struct + */ +void selinux_ima_measure_state(struct selinux_state *state) +{ + WARN_ON(mutex_is_locked(&state->policy_mutex)); + + mutex_lock(&state->policy_mutex); + selinux_ima_measure_state_locked(state); + mutex_unlock(&state->policy_mutex); +} diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index ba2e01a6955c..62d19bccf3de 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -242,11 +242,12 @@ struct security_class_mapping secclass_map[] = { { "infiniband_endport", { "manage_subnet", NULL } }, { "bpf", - {"map_create", "map_read", "map_write", "prog_load", "prog_run"} }, + { "map_create", "map_read", "map_write", "prog_load", "prog_run", + NULL } }, { "xdp_socket", { COMMON_SOCK_PERMS, NULL } }, { "perf_event", - {"open", "cpu", "kernel", "tracepoint", "read", "write"} }, + { "open", "cpu", "kernel", "tracepoint", "read", "write", NULL } }, { "lockdown", { "integrity", "confidentiality", NULL } }, { "anon_inode", diff --git a/security/selinux/include/ima.h b/security/selinux/include/ima.h index d69c36611423..75ca92b4a462 100644 --- a/security/selinux/include/ima.h +++ b/security/selinux/include/ima.h @@ -15,10 +15,16 @@ #ifdef CONFIG_IMA extern void selinux_ima_measure_state(struct selinux_state *selinux_state); +extern void selinux_ima_measure_state_locked( + struct selinux_state *selinux_state); #else static inline void selinux_ima_measure_state(struct selinux_state *selinux_state) { } +static inline void selinux_ima_measure_state_locked( + struct selinux_state *selinux_state) +{ +} #endif #endif /* _SELINUX_IMA_H_ */ diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index ca4d7ab6a835..2953132408bf 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -188,4 +188,10 @@ static inline u32 current_sid(void) return tsec->sid; } +static inline struct superblock_security_struct *selinux_superblock( + const struct super_block *superblock) +{ + return superblock->s_security + selinux_blob_sizes.lbs_superblock; +} + #endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index 7650de048570..ac0ece01305a 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -426,7 +426,7 @@ extern struct page *selinux_kernel_status_page(struct selinux_state *state); #define SELINUX_KERNEL_STATUS_VERSION 1 struct selinux_kernel_status { - u32 version; /* version number of thie structure */ + u32 version; /* version number of the structure */ u32 sequence; /* sequence number of seqlock logic */ u32 enforcing; /* current setting of enforcing mode */ u32 policyload; /* times of policy reloaded */ diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c index b69231918686..d59276f48d4f 100644 --- a/security/selinux/nlmsgtab.c +++ b/security/selinux/nlmsgtab.c @@ -88,6 +88,9 @@ static const struct nlmsg_perm nlmsg_route_perms[] = { RTM_NEWVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, { RTM_DELVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, { RTM_GETVLAN, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_READ }, }; static const struct nlmsg_perm nlmsg_tcpdiag_perms[] = @@ -171,7 +174,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm) * structures at the top of this file with the new mappings * before updating the BUILD_BUG_ON() macro! */ - BUILD_BUG_ON(RTM_MAX != (RTM_NEWVLAN + 3)); + BUILD_BUG_ON(RTM_MAX != (RTM_NEWNEXTHOPBUCKET + 3)); err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, sizeof(nlmsg_route_perms)); break; diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index fff6babeeae6..e4cd7cb856f3 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -41,6 +41,7 @@ #include "security.h" #include "objsec.h" #include "conditional.h" +#include "ima.h" enum sel_inos { SEL_ROOT_INO = 2, @@ -182,6 +183,8 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf, selinux_status_update_setenforce(state, new_value); if (!new_value) call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + + selinux_ima_measure_state(state); } length = count; out: @@ -758,6 +761,9 @@ static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, checkreqprot_set(fsi->state, (new_value ? 1 : 0)); length = count; + + selinux_ima_measure_state(fsi->state); + out: kfree(page); return length; diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c index 3881787ce492..b8f6b3e0a921 100644 --- a/security/selinux/ss/hashtab.c +++ b/security/selinux/ss/hashtab.c @@ -13,7 +13,7 @@ static struct kmem_cache *hashtab_node_cachep __ro_after_init; /* * Here we simply round the number of elements up to the nearest power of two. - * I tried also other options like rouding down or rounding to the closest + * I tried also other options like rounding down or rounding to the closest * power of two (up or down based on which is closer), but I was unable to * find any significant difference in lookup/insert performance that would * justify switching to a different (less intuitive) formula. It could be that diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 301633145040..0a5ce001609b 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -47,6 +47,7 @@ #include <linux/sched.h> #include <linux/audit.h> #include <linux/vmalloc.h> +#include <linux/lsm_hooks.h> #include <net/netlabel.h> #include "flask.h" @@ -2202,7 +2203,7 @@ static void selinux_notify_policy_change(struct selinux_state *state, selinux_status_update_policyload(state, seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); - selinux_ima_measure_state(state); + selinux_ima_measure_state_locked(state); } void selinux_policy_commit(struct selinux_state *state, @@ -2955,7 +2956,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb) struct sidtab *sidtab; int rc; struct ocontext *c; - struct superblock_security_struct *sbsec = sb->s_security; + struct superblock_security_struct *sbsec = selinux_superblock(sb); const char *fstype = sb->s_type->name; if (!selinux_initialized(state)) { diff --git a/security/smack/smack.h b/security/smack/smack.h index a9768b12716b..c3cfbdf4944a 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -357,6 +357,12 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) return ipc->security + smack_blob_sizes.lbs_ipc; } +static inline struct superblock_smack *smack_superblock( + const struct super_block *superblock) +{ + return superblock->s_security + smack_blob_sizes.lbs_superblock; +} + /* * Is the directory transmuting? */ @@ -383,7 +389,23 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp) return tsp->smk_task; } -static inline struct smack_known *smk_of_task_struct( +static inline struct smack_known *smk_of_task_struct_subj( + const struct task_struct *t) +{ + struct smack_known *skp; + const struct cred *cred; + + rcu_read_lock(); + + cred = rcu_dereference(t->cred); + skp = smk_of_task(smack_cred(cred)); + + rcu_read_unlock(); + + return skp; +} + +static inline struct smack_known *smk_of_task_struct_obj( const struct task_struct *t) { struct smack_known *skp; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 12a45e61c1a5..223a6da0e6dc 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -159,7 +159,7 @@ static int smk_bu_current(char *note, struct smack_known *oskp, static int smk_bu_task(struct task_struct *otp, int mode, int rc) { struct task_smack *tsp = smack_cred(current_cred()); - struct smack_known *smk_task = smk_of_task_struct(otp); + struct smack_known *smk_task = smk_of_task_struct_obj(otp); char acc[SMK_NUM_ACCESS_TYPE + 1]; if (rc <= 0) @@ -479,7 +479,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) { struct smack_known *skp; - skp = smk_of_task_struct(ctp); + skp = smk_of_task_struct_obj(ctp); return smk_ptrace_rule_check(current, skp, mode, __func__); } @@ -535,12 +535,7 @@ static int smack_syslog(int typefrom_file) */ static int smack_sb_alloc_security(struct super_block *sb) { - struct superblock_smack *sbsp; - - sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); - - if (sbsp == NULL) - return -ENOMEM; + struct superblock_smack *sbsp = smack_superblock(sb); sbsp->smk_root = &smack_known_floor; sbsp->smk_default = &smack_known_floor; @@ -549,22 +544,10 @@ static int smack_sb_alloc_security(struct super_block *sb) /* * SMK_SB_INITIALIZED will be zero from kzalloc. */ - sb->s_security = sbsp; return 0; } -/** - * smack_sb_free_security - free a superblock blob - * @sb: the superblock getting the blob - * - */ -static void smack_sb_free_security(struct super_block *sb) -{ - kfree(sb->s_security); - sb->s_security = NULL; -} - struct smack_mnt_opts { const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute; }; @@ -772,7 +755,7 @@ static int smack_set_mnt_opts(struct super_block *sb, { struct dentry *root = sb->s_root; struct inode *inode = d_backing_inode(root); - struct superblock_smack *sp = sb->s_security; + struct superblock_smack *sp = smack_superblock(sb); struct inode_smack *isp; struct smack_known *skp; struct smack_mnt_opts *opts = mnt_opts; @@ -871,7 +854,7 @@ static int smack_set_mnt_opts(struct super_block *sb, */ static int smack_sb_statfs(struct dentry *dentry) { - struct superblock_smack *sbp = dentry->d_sb->s_security; + struct superblock_smack *sbp = smack_superblock(dentry->d_sb); int rc; struct smk_audit_info ad; @@ -905,7 +888,7 @@ static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; - sbsp = inode->i_sb->s_security; + sbsp = smack_superblock(inode->i_sb); if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && isp->smk_task != sbsp->smk_root) return 0; @@ -1157,7 +1140,7 @@ static int smack_inode_rename(struct inode *old_inode, */ static int smack_inode_permission(struct inode *inode, int mask) { - struct superblock_smack *sbsp = inode->i_sb->s_security; + struct superblock_smack *sbsp = smack_superblock(inode->i_sb); struct smk_audit_info ad; int no_block = mask & MAY_NOT_BLOCK; int rc; @@ -1400,7 +1383,7 @@ static int smack_inode_removexattr(struct user_namespace *mnt_userns, */ if (strcmp(name, XATTR_NAME_SMACK) == 0) { struct super_block *sbp = dentry->d_sb; - struct superblock_smack *sbsp = sbp->s_security; + struct superblock_smack *sbsp = smack_superblock(sbp); isp->smk_inode = sbsp->smk_default; } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) @@ -1670,7 +1653,7 @@ static int smack_mmap_file(struct file *file, isp = smack_inode(file_inode(file)); if (isp->smk_mmap == NULL) return 0; - sbsp = file_inode(file)->i_sb->s_security; + sbsp = smack_superblock(file_inode(file)->i_sb); if (sbsp->smk_flags & SMK_SB_UNTRUSTED && isp->smk_mmap != sbsp->smk_root) return -EACCES; @@ -2033,7 +2016,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access, const char *caller) { struct smk_audit_info ad; - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_subj(p); int rc; smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); @@ -2078,15 +2061,29 @@ static int smack_task_getsid(struct task_struct *p) } /** - * smack_task_getsecid - get the secid of the task - * @p: the object task + * smack_task_getsecid_subj - get the subjective secid of the task + * @p: the task * @secid: where to put the result * - * Sets the secid to contain a u32 version of the smack label. + * Sets the secid to contain a u32 version of the task's subjective smack label. + */ +static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid) +{ + struct smack_known *skp = smk_of_task_struct_subj(p); + + *secid = skp->smk_secid; +} + +/** + * smack_task_getsecid_obj - get the objective secid of the task + * @p: the task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the task's objective smack label. */ -static void smack_task_getsecid(struct task_struct *p, u32 *secid) +static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) { - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_obj(p); *secid = skp->smk_secid; } @@ -2174,7 +2171,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, { struct smk_audit_info ad; struct smack_known *skp; - struct smack_known *tkp = smk_of_task_struct(p); + struct smack_known *tkp = smk_of_task_struct_obj(p); int rc; if (!sig) @@ -2212,7 +2209,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, static void smack_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_smack *isp = smack_inode(inode); - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_obj(p); isp->smk_inode = skp; isp->smk_flags |= SMK_INODE_INSTANT; @@ -3285,7 +3282,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) return; sbp = inode->i_sb; - sbsp = sbp->s_security; + sbsp = smack_superblock(sbp); /* * We're going to use the superblock default label * if there's no label on the file. @@ -3483,7 +3480,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) */ static int smack_getprocattr(struct task_struct *p, char *name, char **value) { - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_subj(p); char *cp; int slen; @@ -4700,6 +4697,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_inode = sizeof(struct inode_smack), .lbs_ipc = sizeof(struct smack_known *), .lbs_msg_msg = sizeof(struct smack_known *), + .lbs_superblock = sizeof(struct superblock_smack), }; static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { @@ -4711,7 +4709,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), - LSM_HOOK_INIT(sb_free_security, smack_sb_free_security), LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts), LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts), LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), @@ -4759,7 +4756,8 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), LSM_HOOK_INIT(task_getsid, smack_task_getsid), - LSM_HOOK_INIT(task_getsecid, smack_task_getsecid), + LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), LSM_HOOK_INIT(task_setnice, smack_task_setnice), LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), |