diff options
Diffstat (limited to 'security/selinux/hooks.c')
| -rw-r--r-- | security/selinux/hooks.c | 212 |
1 files changed, 182 insertions, 30 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 340b2bbbb2dd..a6bf90ace84c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -85,13 +85,15 @@ #include <linux/export.h> #include <linux/msg.h> #include <linux/shm.h> +#include <uapi/linux/shm.h> #include <linux/bpf.h> #include <linux/kernfs.h> #include <linux/stringhash.h> /* for hashlen_string() */ #include <uapi/linux/mount.h> #include <linux/fsnotify.h> #include <linux/fanotify.h> -#include <linux/io_uring.h> +#include <linux/io_uring/cmd.h> +#include <uapi/linux/lsm.h> #include "avc.h" #include "objsec.h" @@ -2313,6 +2315,19 @@ static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm) new_tsec->keycreate_sid = 0; new_tsec->sockcreate_sid = 0; + /* + * Before policy is loaded, label any task outside kernel space + * as SECINITSID_INIT, so that any userspace tasks surviving from + * early boot end up with a label different from SECINITSID_KERNEL + * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL). + */ + if (!selinux_initialized()) { + new_tsec->sid = SECINITSID_INIT; + /* also clear the exec_sid just in case */ + new_tsec->exec_sid = 0; + return 0; + } + if (old_tsec->exec_sid) { new_tsec->sid = old_tsec->exec_sid; /* Reset exec SID on execve. */ @@ -3725,6 +3740,33 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, return error; } +static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + /* + * If we are in a 64-bit kernel running 32-bit userspace, we need to + * make sure we don't compare 32-bit flags to 64-bit flags. + */ + switch (cmd) { + case FS_IOC32_GETFLAGS: + cmd = FS_IOC_GETFLAGS; + break; + case FS_IOC32_SETFLAGS: + cmd = FS_IOC_SETFLAGS; + break; + case FS_IOC32_GETVERSION: + cmd = FS_IOC_GETVERSION; + break; + case FS_IOC32_SETVERSION: + cmd = FS_IOC_SETVERSION; + break; + default: + break; + } + + return selinux_file_ioctl(file, cmd, arg); +} + static int default_noexec __ro_after_init; static int file_map_prot_check(struct file *file, unsigned long prot, int shared) @@ -4547,6 +4589,21 @@ static int sock_has_perm(struct sock *sk, u32 perms) if (sksec->sid == SECINITSID_KERNEL) return 0; + /* + * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that + * inherited the kernel context from early boot used to be skipped + * here, so preserve that behavior unless the capability is set. + * + * By setting the capability the policy signals that it is ready + * for this quirk to be fixed. Note that sockets created by a kernel + * thread or a usermode helper executed without a transition will + * still be skipped in this check regardless of the policycap + * setting. + */ + if (!selinux_policycap_userspace_initial_context() && + sksec->sid == SECINITSID_INIT) + return 0; + ad_net_init_from_sk(&ad, &net, sk); return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms, @@ -4661,6 +4718,13 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in return -EINVAL; addr4 = (struct sockaddr_in *)address; if (family_sa == AF_UNSPEC) { + if (family == PF_INET6) { + /* Length check from inet6_bind_sk() */ + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + /* Family check from __inet6_bind() */ + goto err_af; + } /* see __inet_bind(), we only want to allow * AF_UNSPEC if the address is INADDR_ANY */ @@ -6278,8 +6342,8 @@ static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) inode_doinit_with_dentry(inode, dentry); } -static int selinux_getprocattr(struct task_struct *p, - const char *name, char **value) +static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p, + char **value) { const struct task_security_struct *__tsec; u32 sid; @@ -6296,20 +6360,27 @@ static int selinux_getprocattr(struct task_struct *p, goto bad; } - if (!strcmp(name, "current")) + switch (attr) { + case LSM_ATTR_CURRENT: sid = __tsec->sid; - else if (!strcmp(name, "prev")) + break; + case LSM_ATTR_PREV: sid = __tsec->osid; - else if (!strcmp(name, "exec")) + break; + case LSM_ATTR_EXEC: sid = __tsec->exec_sid; - else if (!strcmp(name, "fscreate")) + break; + case LSM_ATTR_FSCREATE: sid = __tsec->create_sid; - else if (!strcmp(name, "keycreate")) + break; + case LSM_ATTR_KEYCREATE: sid = __tsec->keycreate_sid; - else if (!strcmp(name, "sockcreate")) + break; + case LSM_ATTR_SOCKCREATE: sid = __tsec->sockcreate_sid; - else { - error = -EINVAL; + break; + default: + error = -EOPNOTSUPP; goto bad; } rcu_read_unlock(); @@ -6327,7 +6398,7 @@ bad: return error; } -static int selinux_setprocattr(const char *name, void *value, size_t size) +static int selinux_lsm_setattr(u64 attr, void *value, size_t size) { struct task_security_struct *tsec; struct cred *new; @@ -6338,23 +6409,31 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) /* * Basic control over ability to set these attributes at all. */ - if (!strcmp(name, "exec")) + switch (attr) { + case LSM_ATTR_EXEC: error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, PROCESS__SETEXEC, NULL); - else if (!strcmp(name, "fscreate")) + break; + case LSM_ATTR_FSCREATE: error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, PROCESS__SETFSCREATE, NULL); - else if (!strcmp(name, "keycreate")) + break; + case LSM_ATTR_KEYCREATE: error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, PROCESS__SETKEYCREATE, NULL); - else if (!strcmp(name, "sockcreate")) + break; + case LSM_ATTR_SOCKCREATE: error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, PROCESS__SETSOCKCREATE, NULL); - else if (!strcmp(name, "current")) + break; + case LSM_ATTR_CURRENT: error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, PROCESS__SETCURRENT, NULL); - else - error = -EINVAL; + break; + default: + error = -EOPNOTSUPP; + break; + } if (error) return error; @@ -6366,13 +6445,14 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) } error = security_context_to_sid(value, size, &sid, GFP_KERNEL); - if (error == -EINVAL && !strcmp(name, "fscreate")) { + if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) { if (!has_cap_mac_admin(true)) { struct audit_buffer *ab; size_t audit_size; - /* We strip a nul only if it is at the end, otherwise the - * context contains a nul and we should audit that */ + /* We strip a nul only if it is at the end, + * otherwise the context contains a nul and + * we should audit that */ if (str[size - 1] == '\0') audit_size = size - 1; else @@ -6383,7 +6463,8 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) if (!ab) return error; audit_log_format(ab, "op=fscreate invalid_context="); - audit_log_n_untrustedstring(ab, value, audit_size); + audit_log_n_untrustedstring(ab, value, + audit_size); audit_log_end(ab); return error; @@ -6406,11 +6487,11 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) checks and may_create for the file creation checks. The operation will then fail if the context is not permitted. */ tsec = selinux_cred(new); - if (!strcmp(name, "exec")) { + if (attr == LSM_ATTR_EXEC) { tsec->exec_sid = sid; - } else if (!strcmp(name, "fscreate")) { + } else if (attr == LSM_ATTR_FSCREATE) { tsec->create_sid = sid; - } else if (!strcmp(name, "keycreate")) { + } else if (attr == LSM_ATTR_KEYCREATE) { if (sid) { error = avc_has_perm(mysid, sid, SECCLASS_KEY, KEY__CREATE, NULL); @@ -6418,14 +6499,13 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) goto abort_change; } tsec->keycreate_sid = sid; - } else if (!strcmp(name, "sockcreate")) { + } else if (attr == LSM_ATTR_SOCKCREATE) { tsec->sockcreate_sid = sid; - } else if (!strcmp(name, "current")) { + } else if (attr == LSM_ATTR_CURRENT) { error = -EINVAL; if (sid == 0) goto abort_change; - /* Only allow single threaded processes to change context */ if (!current_is_single_threaded()) { error = security_bounded_transition(tsec->sid, sid); if (error) @@ -6462,6 +6542,69 @@ abort_change: return error; } +/** + * selinux_getselfattr - Get SELinux current task attributes + * @attr: the requested attribute + * @ctx: buffer to receive the result + * @size: buffer size (input), buffer size used (output) + * @flags: unused + * + * Fill the passed user space @ctx with the details of the requested + * attribute. + * + * Returns the number of attributes on success, an error code otherwise. + * There will only ever be one attribute. + */ +static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx, + size_t *size, u32 flags) +{ + int rc; + char *val; + int val_len; + + val_len = selinux_lsm_getattr(attr, current, &val); + if (val_len < 0) + return val_len; + rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0); + kfree(val); + return (!rc ? 1 : rc); +} + +static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx, + size_t size, u32 flags) +{ + int rc; + + rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len); + if (rc > 0) + return 0; + return rc; +} + +static int selinux_getprocattr(struct task_struct *p, + const char *name, char **value) +{ + unsigned int attr = lsm_name_to_attr(name); + int rc; + + if (attr) { + rc = selinux_lsm_getattr(attr, p, value); + if (rc != -EOPNOTSUPP) + return rc; + } + + return -EINVAL; +} + +static int selinux_setprocattr(const char *name, void *value, size_t size) +{ + int attr = lsm_name_to_attr(name); + + if (attr) + return selinux_lsm_setattr(attr, value, size); + return -EINVAL; +} + static int selinux_ismaclabel(const char *name) { return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0); @@ -6944,6 +7087,11 @@ static int selinux_uring_cmd(struct io_uring_cmd *ioucmd) } #endif /* CONFIG_IO_URING */ +static const struct lsm_id selinux_lsmid = { + .name = "selinux", + .id = LSM_ID_SELINUX, +}; + /* * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order: * 1. any hooks that don't belong to (2.) or (3.) below, @@ -7030,6 +7178,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(file_permission, selinux_file_permission), LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl), + LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat), LSM_HOOK_INIT(mmap_file, selinux_mmap_file), LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr), LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect), @@ -7085,6 +7234,8 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate), + LSM_HOOK_INIT(getselfattr, selinux_getselfattr), + LSM_HOOK_INIT(setselfattr, selinux_setselfattr), LSM_HOOK_INIT(getprocattr, selinux_getprocattr), LSM_HOOK_INIT(setprocattr, selinux_setprocattr), @@ -7264,7 +7415,8 @@ static __init int selinux_init(void) hashtab_cache_init(); - security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux"); + security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), + &selinux_lsmid); if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET)) panic("SELinux: Unable to register AVC netcache callback\n"); |