From 9e48858f7d36a6a3849f1d1b40c3bf5624b4ee7c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 7 May 2009 19:26:19 +1000 Subject: security: rename ptrace_may_access => ptrace_access_check The ->ptrace_may_access() methods are named confusingly - the real ptrace_may_access() returns a bool, while these security checks have a retval convention. Rename it to ptrace_access_check, to reduce the confusion factor. [ Impact: cleanup, no code changed ] Signed-off-by: Ingo Molnar Signed-off-by: James Morris --- security/capability.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security/capability.c') diff --git a/security/capability.c b/security/capability.c index 21b6cead6a8e..f218dd361647 100644 --- a/security/capability.c +++ b/security/capability.c @@ -863,7 +863,7 @@ struct security_operations default_security_ops = { void security_fixup_ops(struct security_operations *ops) { - set_to_cap_if_null(ops, ptrace_may_access); + set_to_cap_if_null(ops, ptrace_access_check); set_to_cap_if_null(ops, ptrace_traceme); set_to_cap_if_null(ops, capget); set_to_cap_if_null(ops, capset); -- cgit v1.2.3 From 7c73875e7dda627040b12c19b01db634fa7f0fd1 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 31 Jul 2009 12:53:58 -0400 Subject: Capabilities: move cap_file_mmap to commoncap.c Currently we duplicate the mmap_min_addr test in cap_file_mmap and in security_file_mmap if !CONFIG_SECURITY. This patch moves cap_file_mmap into commoncap.c and then calls that function directly from security_file_mmap ifndef CONFIG_SECURITY like all of the other capability checks are done. Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 7 ++++--- security/capability.c | 9 --------- security/commoncap.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 12 deletions(-) (limited to 'security/capability.c') diff --git a/include/linux/security.h b/include/linux/security.h index 145909165dbf..963a48fc3005 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -66,6 +66,9 @@ extern int cap_inode_setxattr(struct dentry *dentry, const char *name, extern int cap_inode_removexattr(struct dentry *dentry, const char *name); extern int cap_inode_need_killpriv(struct dentry *dentry); extern int cap_inode_killpriv(struct dentry *dentry); +extern int cap_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags, + unsigned long addr, unsigned long addr_only); extern int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags); extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5); @@ -2197,9 +2200,7 @@ static inline int security_file_mmap(struct file *file, unsigned long reqprot, unsigned long addr, unsigned long addr_only) { - if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) - return -EACCES; - return 0; + return cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); } static inline int security_file_mprotect(struct vm_area_struct *vma, diff --git a/security/capability.c b/security/capability.c index f218dd361647..ec0573054024 100644 --- a/security/capability.c +++ b/security/capability.c @@ -330,15 +330,6 @@ static int cap_file_ioctl(struct file *file, unsigned int command, return 0; } -static int cap_file_mmap(struct file *file, unsigned long reqprot, - unsigned long prot, unsigned long flags, - unsigned long addr, unsigned long addr_only) -{ - if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) - return -EACCES; - return 0; -} - static int cap_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot) { diff --git a/security/commoncap.c b/security/commoncap.c index aa97704564d4..3852e9432801 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -984,3 +984,33 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } + +/* + * cap_file_mmap - check if able to map given addr + * @file: unused + * @reqprot: unused + * @prot: unused + * @flags: unused + * @addr: address attempting to be mapped + * @addr_only: unused + * + * If the process is attempting to map memory below 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. + */ +int cap_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags, + unsigned long addr, unsigned long addr_only) +{ + int ret = 0; + + if (addr < mmap_min_addr) { + ret = cap_capable(current, current_cred(), CAP_SYS_RAWIO, + SECURITY_CAP_AUDIT); + /* set PF_SUPERPRIV if it turns out we allow the low mmap */ + if (ret == 0) + current->flags |= PF_SUPERPRIV; + } + return ret; +} -- cgit v1.2.3 From 9188499cdb117d86a1ea6b04374095b098d56936 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 13 Aug 2009 09:44:57 -0400 Subject: security: introducing security_request_module Calling request_module() will trigger a userspace upcall which will load a new module into the kernel. This can be a dangerous event if the process able to trigger request_module() is able to control either the modprobe binary or the module binary. This patch adds a new security hook to request_module() which can be used by an LSM to control a processes ability to call request_module(). Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 10 ++++++++++ kernel/kmod.c | 4 ++++ security/capability.c | 6 ++++++ security/security.c | 5 +++++ 4 files changed, 25 insertions(+) (limited to 'security/capability.c') diff --git a/include/linux/security.h b/include/linux/security.h index 57ead99d2593..1e3dd86eea99 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -678,6 +678,9 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @inode points to the inode to use as a reference. * The current task must be the one that nominated @inode. * Return 0 if successful. + * @kernel_module_request: + * Ability to trigger the kernel to automatically upcall to userspace for + * userspace to load a kernel module with the given name. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates @@ -1489,6 +1492,7 @@ struct security_operations { void (*cred_commit)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); + int (*kernel_module_request)(void); int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags); int (*task_fix_setuid) (struct cred *new, const struct cred *old, int flags); @@ -1741,6 +1745,7 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_commit_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); +int security_kernel_module_request(void); int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); @@ -2292,6 +2297,11 @@ static inline int security_kernel_create_files_as(struct cred *cred, return 0; } +static inline int security_kernel_module_request(void) +{ + return 0; +} + static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { diff --git a/kernel/kmod.c b/kernel/kmod.c index 385c31a1bdbf..5a7ae57f983f 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -78,6 +78,10 @@ int __request_module(bool wait, const char *fmt, ...) #define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */ static int kmod_loop_msg; + ret = security_kernel_module_request(); + if (ret) + return ret; + va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); diff --git a/security/capability.c b/security/capability.c index ec0573054024..1b943f54b2ea 100644 --- a/security/capability.c +++ b/security/capability.c @@ -396,6 +396,11 @@ static int cap_kernel_create_files_as(struct cred *new, struct inode *inode) return 0; } +static int cap_kernel_module_request(void) +{ + return 0; +} + static int cap_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { return 0; @@ -945,6 +950,7 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, cred_commit); set_to_cap_if_null(ops, kernel_act_as); set_to_cap_if_null(ops, kernel_create_files_as); + set_to_cap_if_null(ops, kernel_module_request); set_to_cap_if_null(ops, task_setuid); set_to_cap_if_null(ops, task_fix_setuid); set_to_cap_if_null(ops, task_setgid); diff --git a/security/security.c b/security/security.c index 4501c5e1f988..0e993f42ce3d 100644 --- a/security/security.c +++ b/security/security.c @@ -709,6 +709,11 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode) return security_ops->kernel_create_files_as(new, inode); } +int security_kernel_module_request(void) +{ + return security_ops->kernel_module_request(); +} + int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { return security_ops->task_setuid(id0, id1, id2, flags); -- cgit v1.2.3 From 2b980dbd77d229eb60588802162c9659726b11f4 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 28 Aug 2009 18:12:43 -0400 Subject: lsm: Add hooks to the TUN driver The TUN driver lacks any LSM hooks which makes it difficult for LSM modules, such as SELinux, to enforce access controls on network traffic generated by TUN users; this is particularly problematic for virtualization apps such as QEMU and KVM. This patch adds three new LSM hooks designed to control the creation and attachment of TUN devices, the hooks are: * security_tun_dev_create() Provides access control for the creation of new TUN devices * security_tun_dev_post_create() Provides the ability to create the necessary socket LSM state for newly created TUN devices * security_tun_dev_attach() Provides access control for attaching to existing, persistent TUN devices and the ability to update the TUN device's socket LSM state as necessary Signed-off-by: Paul Moore Acked-by: Eric Paris Acked-by: Serge Hallyn Acked-by: David S. Miller Signed-off-by: James Morris --- drivers/net/tun.c | 22 +++++++++++++++------- include/linux/security.h | 31 +++++++++++++++++++++++++++++++ security/capability.c | 19 +++++++++++++++++++ security/security.c | 18 ++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) (limited to 'security/capability.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 42b6c6319bc2..87214a257d2a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -130,17 +130,10 @@ static inline struct tun_sock *tun_sk(struct sock *sk) static int tun_attach(struct tun_struct *tun, struct file *file) { struct tun_file *tfile = file->private_data; - const struct cred *cred = current_cred(); int err; ASSERT_RTNL(); - /* Check permissions */ - if (((tun->owner != -1 && cred->euid != tun->owner) || - (tun->group != -1 && !in_egroup_p(tun->group))) && - !capable(CAP_NET_ADMIN)) - return -EPERM; - netif_tx_lock_bh(tun->dev); err = -EINVAL; @@ -926,6 +919,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) dev = __dev_get_by_name(net, ifr->ifr_name); if (dev) { + const struct cred *cred = current_cred(); + if (ifr->ifr_flags & IFF_TUN_EXCL) return -EBUSY; if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) @@ -935,6 +930,14 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) else return -EINVAL; + if (((tun->owner != -1 && cred->euid != tun->owner) || + (tun->group != -1 && !in_egroup_p(tun->group))) && + !capable(CAP_NET_ADMIN)) + return -EPERM; + err = security_tun_dev_attach(tun->sk); + if (err < 0) + return err; + err = tun_attach(tun, file); if (err < 0) return err; @@ -947,6 +950,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) if (!capable(CAP_NET_ADMIN)) return -EPERM; + err = security_tun_dev_create(); + if (err < 0) + return err; /* Set dev type */ if (ifr->ifr_flags & IFF_TUN) { @@ -989,6 +995,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) tun->sk = sk; container_of(sk, struct tun_sock, sk)->tun = tun; + security_tun_dev_post_create(sk); + tun_net_init(dev); if (strchr(dev->name, '%')) { diff --git a/include/linux/security.h b/include/linux/security.h index a16d6b7c4ebe..40ba39ea68ce 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -998,6 +998,17 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Sets the connection's peersid to the secmark on skb. * @req_classify_flow: * Sets the flow's sid to the openreq sid. + * @tun_dev_create: + * Check permissions prior to creating a new TUN device. + * @tun_dev_post_create: + * This hook allows a module to update or allocate a per-socket security + * structure. + * @sk contains the newly created sock structure. + * @tun_dev_attach: + * Check permissions prior to attaching to a persistent TUN device. This + * hook can also be used by the module to update any security state + * associated with the TUN device's sock structure. + * @sk contains the existing sock structure. * * Security hooks for XFRM operations. * @@ -1597,6 +1608,9 @@ struct security_operations { void (*inet_csk_clone) (struct sock *newsk, const struct request_sock *req); void (*inet_conn_established) (struct sock *sk, struct sk_buff *skb); void (*req_classify_flow) (const struct request_sock *req, struct flowi *fl); + int (*tun_dev_create)(void); + void (*tun_dev_post_create)(struct sock *sk); + int (*tun_dev_attach)(struct sock *sk); #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM @@ -2586,6 +2600,9 @@ void security_inet_csk_clone(struct sock *newsk, const struct request_sock *req); void security_inet_conn_established(struct sock *sk, struct sk_buff *skb); +int security_tun_dev_create(void); +void security_tun_dev_post_create(struct sock *sk); +int security_tun_dev_attach(struct sock *sk); #else /* CONFIG_SECURITY_NETWORK */ static inline int security_unix_stream_connect(struct socket *sock, @@ -2736,6 +2753,20 @@ static inline void security_inet_conn_established(struct sock *sk, struct sk_buff *skb) { } + +static inline int security_tun_dev_create(void) +{ + return 0; +} + +static inline void security_tun_dev_post_create(struct sock *sk) +{ +} + +static inline int security_tun_dev_attach(struct sock *sk) +{ + return 0; +} #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM diff --git a/security/capability.c b/security/capability.c index 1b943f54b2ea..06400cf07757 100644 --- a/security/capability.c +++ b/security/capability.c @@ -706,10 +706,26 @@ static void cap_inet_conn_established(struct sock *sk, struct sk_buff *skb) { } + + static void cap_req_classify_flow(const struct request_sock *req, struct flowi *fl) { } + +static int cap_tun_dev_create(void) +{ + return 0; +} + +static void cap_tun_dev_post_create(struct sock *sk) +{ +} + +static int cap_tun_dev_attach(struct sock *sk) +{ + return 0; +} #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM @@ -1026,6 +1042,9 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, inet_csk_clone); set_to_cap_if_null(ops, inet_conn_established); set_to_cap_if_null(ops, req_classify_flow); + set_to_cap_if_null(ops, tun_dev_create); + set_to_cap_if_null(ops, tun_dev_post_create); + set_to_cap_if_null(ops, tun_dev_attach); #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM set_to_cap_if_null(ops, xfrm_policy_alloc_security); diff --git a/security/security.c b/security/security.c index 0e993f42ce3d..f88eaf6b14cc 100644 --- a/security/security.c +++ b/security/security.c @@ -1117,6 +1117,24 @@ void security_inet_conn_established(struct sock *sk, security_ops->inet_conn_established(sk, skb); } +int security_tun_dev_create(void) +{ + return security_ops->tun_dev_create(); +} +EXPORT_SYMBOL(security_tun_dev_create); + +void security_tun_dev_post_create(struct sock *sk) +{ + return security_ops->tun_dev_post_create(sk); +} +EXPORT_SYMBOL(security_tun_dev_post_create); + +int security_tun_dev_attach(struct sock *sk) +{ + return security_ops->tun_dev_attach(sk); +} +EXPORT_SYMBOL(security_tun_dev_attach); + #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM -- cgit v1.2.3 From ee18d64c1f632043a02e6f5ba5e045bb26a5465f Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 2 Sep 2009 09:14:21 +0100 Subject: KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include #include #include #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells Signed-off-by: James Morris --- Documentation/keys.txt | 20 +++++++++ arch/alpha/kernel/signal.c | 2 + arch/arm/kernel/signal.c | 2 + arch/avr32/kernel/signal.c | 2 + arch/cris/kernel/ptrace.c | 2 + arch/frv/kernel/signal.c | 2 + arch/h8300/kernel/signal.c | 2 + arch/ia64/kernel/process.c | 2 + arch/m32r/kernel/signal.c | 2 + arch/mips/kernel/signal.c | 2 + arch/mn10300/kernel/signal.c | 2 + arch/parisc/kernel/signal.c | 2 + arch/s390/kernel/signal.c | 2 + arch/sh/kernel/signal_32.c | 2 + arch/sh/kernel/signal_64.c | 2 + arch/sparc/kernel/signal_32.c | 2 + arch/sparc/kernel/signal_64.c | 3 ++ arch/x86/kernel/signal.c | 2 + include/linux/cred.h | 1 + include/linux/key.h | 3 ++ include/linux/keyctl.h | 1 + include/linux/sched.h | 1 + include/linux/security.h | 38 ++++++++++++++++ kernel/cred.c | 43 ++++++++++++++++++ security/capability.c | 19 ++++++++ security/keys/compat.c | 3 ++ security/keys/gc.c | 1 + security/keys/internal.h | 1 + security/keys/keyctl.c | 102 ++++++++++++++++++++++++++++++++++++++++++ security/keys/process_keys.c | 49 ++++++++++++++++++++ security/security.c | 17 +++++++ security/selinux/hooks.c | 28 ++++++++++++ security/smack/smack_lsm.c | 30 +++++++++++++ security/tomoyo/tomoyo.c | 17 +++++++ 34 files changed, 409 insertions(+) (limited to 'security/capability.c') diff --git a/Documentation/keys.txt b/Documentation/keys.txt index 203487e9b1d8..e4dbbdb1bd96 100644 --- a/Documentation/keys.txt +++ b/Documentation/keys.txt @@ -757,6 +757,26 @@ The keyctl syscall functions are: successful. + (*) Install the calling process's session keyring on its parent. + + long keyctl(KEYCTL_SESSION_TO_PARENT); + + This functions attempts to install the calling process's session keyring + on to the calling process's parent, replacing the parent's current session + keyring. + + The calling process must have the same ownership as its parent, the + keyring must have the same ownership as the calling process, the calling + process must have LINK permission on the keyring and the active LSM module + mustn't deny permission, otherwise error EPERM will be returned. + + Error ENOMEM will be returned if there was insufficient memory to complete + the operation, otherwise 0 will be returned to indicate success. + + The keyring will be replaced next time the parent process leaves the + kernel and resumes executing userspace. + + =============== KERNEL SERVICES =============== diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index 04e17c1f0f1b..d91aaa747050 100644 --- a/arch/alpha/kernel/signal.c +++ b/arch/alpha/kernel/signal.c @@ -687,5 +687,7 @@ do_notify_resume(struct pt_regs *regs, struct switch_stack *sw, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 13dec276927a..ea4ad3a43c88 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -711,5 +711,7 @@ do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) if (thread_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c index 62d242e2d033..de9f7fe2aefa 100644 --- a/arch/avr32/kernel/signal.c +++ b/arch/avr32/kernel/signal.c @@ -326,5 +326,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) if (ti->flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/cris/kernel/ptrace.c b/arch/cris/kernel/ptrace.c index 4f06d7fb43dd..32e9d5ee895b 100644 --- a/arch/cris/kernel/ptrace.c +++ b/arch/cris/kernel/ptrace.c @@ -40,5 +40,7 @@ void do_notify_resume(int canrestart, struct pt_regs *regs, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c index 4a7a62c6e783..6b0a2b6fed6a 100644 --- a/arch/frv/kernel/signal.c +++ b/arch/frv/kernel/signal.c @@ -572,6 +572,8 @@ asmlinkage void do_notify_resume(__u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(__frame); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } /* end do_notify_resume() */ diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c index 56b3ab7dbbb0..abac3ee8c52a 100644 --- a/arch/h8300/kernel/signal.c +++ b/arch/h8300/kernel/signal.c @@ -556,5 +556,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 5d7c0e5b9e76..89969e950045 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -192,6 +192,8 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) if (test_thread_flag(TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(&scr->pt); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } /* copy user rbs to kernel rbs */ diff --git a/arch/m32r/kernel/signal.c b/arch/m32r/kernel/signal.c index 3220258be188..f80bac17c65c 100644 --- a/arch/m32r/kernel/signal.c +++ b/arch/m32r/kernel/signal.c @@ -411,6 +411,8 @@ void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } clear_thread_flag(TIF_IRET); diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index a3d1015471de..c2acf31874a4 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -704,5 +704,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c index feb2f2e810db..a21f43bc68e2 100644 --- a/arch/mn10300/kernel/signal.c +++ b/arch/mn10300/kernel/signal.c @@ -568,5 +568,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(__frame); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c index b3bfc4326703..5ca1c02b805a 100644 --- a/arch/parisc/kernel/signal.c +++ b/arch/parisc/kernel/signal.c @@ -649,5 +649,7 @@ void do_notify_resume(struct pt_regs *regs, long in_syscall) if (test_thread_flag(TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c index 062bd64e65fa..6b4fef877f9d 100644 --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -536,4 +536,6 @@ void do_notify_resume(struct pt_regs *regs) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index b5afbec1db59..04a21883f327 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -640,5 +640,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c index 0663a0ee6021..9e5c9b1d7e98 100644 --- a/arch/sh/kernel/signal_64.c +++ b/arch/sh/kernel/signal_64.c @@ -772,5 +772,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c index 181d069a2d44..7ce1a1005b1d 100644 --- a/arch/sparc/kernel/signal_32.c +++ b/arch/sparc/kernel/signal_32.c @@ -590,6 +590,8 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index ec82d76dc6f2..647afbda7ae1 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -613,5 +613,8 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } } + diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 4c578751e94e..81e58238c4ce 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -869,6 +869,8 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (current->replacement_session_keyring) + key_replace_session_keyring(); } #ifdef CONFIG_X86_32 diff --git a/include/linux/cred.h b/include/linux/cred.h index 85439abdbc80..24520a539c6f 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -152,6 +152,7 @@ struct cred { extern void __put_cred(struct cred *); extern void exit_creds(struct task_struct *); extern int copy_creds(struct task_struct *, unsigned long); +extern struct cred *cred_alloc_blank(void); extern struct cred *prepare_creds(void); extern struct cred *prepare_exec_creds(void); extern struct cred *prepare_usermodehelper_creds(void); diff --git a/include/linux/key.h b/include/linux/key.h index 33e0165de100..cd50dfa1d4c2 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -278,6 +278,8 @@ static inline key_serial_t key_serial(struct key *key) extern ctl_table key_sysctls[]; #endif +extern void key_replace_session_keyring(void); + /* * the userspace interface */ @@ -300,6 +302,7 @@ extern void key_init(void); #define key_fsuid_changed(t) do { } while(0) #define key_fsgid_changed(t) do { } while(0) #define key_init() do { } while(0) +#define key_replace_session_keyring() do { } while(0) #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index c0688eb72093..bd383f1944fb 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -52,5 +52,6 @@ #define KEYCTL_SET_TIMEOUT 15 /* set key timeout */ #define KEYCTL_ASSUME_AUTHORITY 16 /* assume request_key() authorisation */ #define KEYCTL_GET_SECURITY 17 /* get key security label */ +#define KEYCTL_SESSION_TO_PARENT 18 /* apply session keyring to parent process */ #endif /* _LINUX_KEYCTL_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 5c7ce13c1696..9304027673b0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1292,6 +1292,7 @@ struct task_struct { struct mutex cred_guard_mutex; /* guard against foreign influences on * credential calculations * (notably. ptrace) */ + struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */ char comm[TASK_COMM_LEN]; /* executable name excluding path - access with [gs]et_task_comm (which lock diff --git a/include/linux/security.h b/include/linux/security.h index 40ba39ea68ce..97de3fe3dd0d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -653,6 +653,11 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * manual page for definitions of the @clone_flags. * @clone_flags contains the flags indicating what should be shared. * Return 0 if permission is granted. + * @cred_alloc_blank: + * @cred points to the credentials. + * @gfp indicates the atomicity of any memory allocations. + * Only allocate sufficient memory and attach to @cred such that + * cred_transfer() will not get ENOMEM. * @cred_free: * @cred points to the credentials. * Deallocate and clear the cred->security field in a set of credentials. @@ -665,6 +670,10 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @new points to the new credentials. * @old points to the original credentials. * Install a new set of credentials. + * @cred_transfer: + * @new points to the new credentials. + * @old points to the original credentials. + * Transfer data from original creds to new creds * @kernel_act_as: * Set the credentials for a kernel service to act as (subjective context). * @new points to the credentials to be modified. @@ -1103,6 +1112,13 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Return the length of the string (including terminating NUL) or -ve if * an error. * May also return 0 (and a NULL buffer pointer) if there is no label. + * @key_session_to_parent: + * Forcibly assign the session keyring from a process to its parent + * process. + * @cred: Pointer to process's credentials + * @parent_cred: Pointer to parent process's credentials + * @keyring: Proposed new session keyring + * Return 0 if permission is granted, -ve error otherwise. * * Security hooks affecting all System V IPC operations. * @@ -1498,10 +1514,12 @@ struct security_operations { int (*dentry_open) (struct file *file, const struct cred *cred); int (*task_create) (unsigned long clone_flags); + int (*cred_alloc_blank) (struct cred *cred, gfp_t gfp); void (*cred_free) (struct cred *cred); int (*cred_prepare)(struct cred *new, const struct cred *old, gfp_t gfp); void (*cred_commit)(struct cred *new, const struct cred *old); + void (*cred_transfer)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); int (*kernel_module_request)(void); @@ -1639,6 +1657,9 @@ struct security_operations { const struct cred *cred, key_perm_t perm); int (*key_getsecurity)(struct key *key, char **_buffer); + int (*key_session_to_parent)(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT @@ -1755,9 +1776,11 @@ int security_file_send_sigiotask(struct task_struct *tsk, int security_file_receive(struct file *file); int security_dentry_open(struct file *file, const struct cred *cred); int security_task_create(unsigned long clone_flags); +int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_commit_creds(struct cred *new, const struct cred *old); +void security_transfer_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(void); @@ -2286,6 +2309,9 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } +static inline void security_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ } + static inline void security_cred_free(struct cred *cred) { } @@ -2301,6 +2327,11 @@ static inline void security_commit_creds(struct cred *new, { } +static inline void security_transfer_creds(struct cred *new, + const struct cred *old) +{ +} + static inline int security_kernel_act_as(struct cred *cred, u32 secid) { return 0; @@ -2923,6 +2954,9 @@ void security_key_free(struct key *key); int security_key_permission(key_ref_t key_ref, const struct cred *cred, key_perm_t perm); int security_key_getsecurity(struct key *key, char **_buffer); +int security_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); #else @@ -2950,6 +2984,10 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) return 0; } +static inline int security_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); + #endif #endif /* CONFIG_KEYS */ diff --git a/kernel/cred.c b/kernel/cred.c index 24dd2f5104b1..006fcab009d5 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -199,6 +199,49 @@ void exit_creds(struct task_struct *tsk) validate_creds(cred); alter_cred_subscribers(cred, -1); put_cred(cred); + + cred = (struct cred *) tsk->replacement_session_keyring; + if (cred) { + tsk->replacement_session_keyring = NULL; + validate_creds(cred); + put_cred(cred); + } +} + +/* + * Allocate blank credentials, such that the credentials can be filled in at a + * later date without risk of ENOMEM. + */ +struct cred *cred_alloc_blank(void) +{ + struct cred *new; + + new = kmem_cache_zalloc(cred_jar, GFP_KERNEL); + if (!new) + return NULL; + +#ifdef CONFIG_KEYS + new->tgcred = kzalloc(sizeof(*new->tgcred), GFP_KERNEL); + if (!new->tgcred) { + kfree(new); + return NULL; + } + atomic_set(&new->tgcred->usage, 1); +#endif + + atomic_set(&new->usage, 1); + + if (security_cred_alloc_blank(new, GFP_KERNEL) < 0) + goto error; + +#ifdef CONFIG_DEBUG_CREDENTIALS + new->magic = CRED_MAGIC; +#endif + return new; + +error: + abort_creds(new); + return NULL; } /** diff --git a/security/capability.c b/security/capability.c index 06400cf07757..93a2ffe65905 100644 --- a/security/capability.c +++ b/security/capability.c @@ -373,6 +373,11 @@ static int cap_task_create(unsigned long clone_flags) return 0; } +static int cap_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + return 0; +} + static void cap_cred_free(struct cred *cred) { } @@ -386,6 +391,10 @@ static void cap_cred_commit(struct cred *new, const struct cred *old) { } +static void cap_cred_transfer(struct cred *new, const struct cred *old) +{ +} + static int cap_kernel_act_as(struct cred *new, u32 secid) { return 0; @@ -836,6 +845,13 @@ static int cap_key_getsecurity(struct key *key, char **_buffer) return 0; } +static int cap_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key) +{ + return 0; +} + #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT @@ -961,9 +977,11 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, file_receive); set_to_cap_if_null(ops, dentry_open); set_to_cap_if_null(ops, task_create); + set_to_cap_if_null(ops, cred_alloc_blank); set_to_cap_if_null(ops, cred_free); set_to_cap_if_null(ops, cred_prepare); set_to_cap_if_null(ops, cred_commit); + set_to_cap_if_null(ops, cred_transfer); set_to_cap_if_null(ops, kernel_act_as); set_to_cap_if_null(ops, kernel_create_files_as); set_to_cap_if_null(ops, kernel_module_request); @@ -1063,6 +1081,7 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, key_free); set_to_cap_if_null(ops, key_permission); set_to_cap_if_null(ops, key_getsecurity); + set_to_cap_if_null(ops, key_session_to_parent); #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT set_to_cap_if_null(ops, audit_rule_init); diff --git a/security/keys/compat.c b/security/keys/compat.c index c766c68a63bc..792c0a611a6d 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -82,6 +82,9 @@ asmlinkage long compat_sys_keyctl(u32 option, case KEYCTL_GET_SECURITY: return keyctl_get_security(arg2, compat_ptr(arg3), arg4); + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + default: return -EOPNOTSUPP; } diff --git a/security/keys/gc.c b/security/keys/gc.c index 44adc325e15c..1e616aef55fd 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -65,6 +65,7 @@ static void key_gc_timer_func(unsigned long data) * - return true if we altered the keyring */ static bool key_gc_keyring(struct key *keyring, time_t limit) + __releases(key_serial_lock) { struct keyring_list *klist; struct key *key; diff --git a/security/keys/internal.h b/security/keys/internal.h index fb830514c337..24ba0307b7ad 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -201,6 +201,7 @@ extern long keyctl_set_timeout(key_serial_t, unsigned); extern long keyctl_assume_authority(key_serial_t); extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, size_t buflen); +extern long keyctl_session_to_parent(void); /* * debugging key validation diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 736d7800f97f..74c968524592 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1228,6 +1228,105 @@ long keyctl_get_security(key_serial_t keyid, return ret; } +/* + * attempt to install the calling process's session keyring on the process's + * parent process + * - the keyring must exist and must grant us LINK permission + * - implements keyctl(KEYCTL_SESSION_TO_PARENT) + */ +long keyctl_session_to_parent(void) +{ + struct task_struct *me, *parent; + const struct cred *mycred, *pcred; + struct cred *cred, *oldcred; + key_ref_t keyring_r; + int ret; + + keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK); + if (IS_ERR(keyring_r)) + return PTR_ERR(keyring_r); + + /* our parent is going to need a new cred struct, a new tgcred struct + * and new security data, so we allocate them here to prevent ENOMEM in + * our parent */ + ret = -ENOMEM; + cred = cred_alloc_blank(); + if (!cred) + goto error_keyring; + + cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r); + keyring_r = NULL; + + me = current; + write_lock_irq(&tasklist_lock); + + parent = me->real_parent; + ret = -EPERM; + + /* the parent mustn't be init and mustn't be a kernel thread */ + if (parent->pid <= 1 || !parent->mm) + goto not_permitted; + + /* the parent must be single threaded */ + if (atomic_read(&parent->signal->count) != 1) + goto not_permitted; + + /* the parent and the child must have different session keyrings or + * there's no point */ + mycred = current_cred(); + pcred = __task_cred(parent); + if (mycred == pcred || + mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) + goto already_same; + + /* the parent must have the same effective ownership and mustn't be + * SUID/SGID */ + if (pcred-> uid != mycred->euid || + pcred->euid != mycred->euid || + pcred->suid != mycred->euid || + pcred-> gid != mycred->egid || + pcred->egid != mycred->egid || + pcred->sgid != mycred->egid) + goto not_permitted; + + /* the keyrings must have the same UID */ + if (pcred ->tgcred->session_keyring->uid != mycred->euid || + mycred->tgcred->session_keyring->uid != mycred->euid) + goto not_permitted; + + /* the LSM must permit the replacement of the parent's keyring with the + * keyring from this process */ + ret = security_key_session_to_parent(mycred, pcred, + key_ref_to_ptr(keyring_r)); + if (ret < 0) + goto not_permitted; + + /* if there's an already pending keyring replacement, then we replace + * that */ + oldcred = parent->replacement_session_keyring; + + /* the replacement session keyring is applied just prior to userspace + * restarting */ + parent->replacement_session_keyring = cred; + cred = NULL; + set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME); + + write_unlock_irq(&tasklist_lock); + if (oldcred) + put_cred(oldcred); + return 0; + +already_same: + ret = 0; +not_permitted: + put_cred(cred); + return ret; + +error_keyring: + key_ref_put(keyring_r); + return ret; +} + /*****************************************************************************/ /* * the key control system call @@ -1313,6 +1412,9 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, (char __user *) arg3, (size_t) arg4); + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + default: return -EOPNOTSUPP; } diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 4739cfbb41b7..5c23afb31ece 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -768,3 +769,51 @@ error: abort_creds(new); return ret; } + +/* + * Replace a process's session keyring when that process resumes userspace on + * behalf of one of its children + */ +void key_replace_session_keyring(void) +{ + const struct cred *old; + struct cred *new; + + if (!current->replacement_session_keyring) + return; + + write_lock_irq(&tasklist_lock); + new = current->replacement_session_keyring; + current->replacement_session_keyring = NULL; + write_unlock_irq(&tasklist_lock); + + if (!new) + return; + + old = current_cred(); + new-> uid = old-> uid; + new-> euid = old-> euid; + new-> suid = old-> suid; + new->fsuid = old->fsuid; + new-> gid = old-> gid; + new-> egid = old-> egid; + new-> sgid = old-> sgid; + new->fsgid = old->fsgid; + new->user = get_uid(old->user); + new->group_info = get_group_info(old->group_info); + + new->securebits = old->securebits; + new->cap_inheritable = old->cap_inheritable; + new->cap_permitted = old->cap_permitted; + new->cap_effective = old->cap_effective; + new->cap_bset = old->cap_bset; + + new->jit_keyring = old->jit_keyring; + new->thread_keyring = key_get(old->thread_keyring); + new->tgcred->tgid = old->tgcred->tgid; + new->tgcred->process_keyring = key_get(old->tgcred->process_keyring); + + security_transfer_creds(new, old); + + commit_creds(new); +} diff --git a/security/security.c b/security/security.c index f88eaf6b14cc..d8b727637f02 100644 --- a/security/security.c +++ b/security/security.c @@ -684,6 +684,11 @@ int security_task_create(unsigned long clone_flags) return security_ops->task_create(clone_flags); } +int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + return security_ops->cred_alloc_blank(cred, gfp); +} + void security_cred_free(struct cred *cred) { security_ops->cred_free(cred); @@ -699,6 +704,11 @@ void security_commit_creds(struct cred *new, const struct cred *old) security_ops->cred_commit(new, old); } +void security_transfer_creds(struct cred *new, const struct cred *old) +{ + security_ops->cred_transfer(new, old); +} + int security_kernel_act_as(struct cred *new, u32 secid) { return security_ops->kernel_act_as(new, secid); @@ -1241,6 +1251,13 @@ int security_key_getsecurity(struct key *key, char **_buffer) return security_ops->key_getsecurity(key, _buffer); } +int security_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key) +{ + return security_ops->key_session_to_parent(cred, parent_cred, key); +} + #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c3bb31ecc5aa..134a9c0d2004 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3232,6 +3232,21 @@ static int selinux_task_create(unsigned long clone_flags) return current_has_perm(current, PROCESS__FORK); } +/* + * allocate the SELinux part of blank credentials + */ +static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + struct task_security_struct *tsec; + + tsec = kzalloc(sizeof(struct task_security_struct), gfp); + if (!tsec) + return -ENOMEM; + + cred->security = tsec; + return 0; +} + /* * detach and free the LSM part of a set of credentials */ @@ -3263,6 +3278,17 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old, return 0; } +/* + * transfer the SELinux data to a blank set of creds + */ +static void selinux_cred_transfer(struct cred *new, const struct cred *old) +{ + const struct task_security_struct *old_tsec = old->security; + struct task_security_struct *tsec = new->security; + + *tsec = *old_tsec; +} + /* * set the security data for a kernel service * - all the creation contexts are set to unlabelled @@ -5469,8 +5495,10 @@ static struct security_operations selinux_ops = { .dentry_open = selinux_dentry_open, .task_create = selinux_task_create, + .cred_alloc_blank = selinux_cred_alloc_blank, .cred_free = selinux_cred_free, .cred_prepare = selinux_cred_prepare, + .cred_transfer = selinux_cred_transfer, .kernel_act_as = selinux_kernel_act_as, .kernel_create_files_as = selinux_kernel_create_files_as, .kernel_module_request = selinux_kernel_module_request, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index c243a2b25832..969f5fee1906 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1079,6 +1079,22 @@ static int smack_file_receive(struct file *file) * Task hooks */ +/** + * smack_cred_alloc_blank - "allocate" blank task-level security credentials + * @new: the new credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a blank set of credentials for modification. This must allocate all + * the memory the LSM module might require such that cred_transfer() can + * complete without error. + */ +static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + cred->security = NULL; + return 0; +} + + /** * smack_cred_free - "free" task-level security credentials * @cred: the credentials in question @@ -1116,6 +1132,18 @@ static void smack_cred_commit(struct cred *new, const struct cred *old) { } +/** + * smack_cred_transfer - Transfer the old credentials to the new credentials + * @new: the new credentials + * @old: the original credentials + * + * Fill in a set of blank credentials from another set of credentials. + */ +static void smack_cred_transfer(struct cred *new, const struct cred *old) +{ + new->security = old->security; +} + /** * smack_kernel_act_as - Set the subjective context in a set of credentials * @new: points to the set of credentials to be modified. @@ -3073,9 +3101,11 @@ struct security_operations smack_ops = { .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, + .cred_alloc_blank = smack_cred_alloc_blank, .cred_free = smack_cred_free, .cred_prepare = smack_cred_prepare, .cred_commit = smack_cred_commit, + .cred_transfer = smack_cred_transfer, .kernel_act_as = smack_kernel_act_as, .kernel_create_files_as = smack_kernel_create_files_as, .task_setpgid = smack_task_setpgid, diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 35a13e7915e4..9548a0984cc4 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -14,6 +14,12 @@ #include "tomoyo.h" #include "realpath.h" +static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp) +{ + new->security = NULL; + return 0; +} + static int tomoyo_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { @@ -25,6 +31,15 @@ static int tomoyo_cred_prepare(struct cred *new, const struct cred *old, return 0; } +static void tomoyo_cred_transfer(struct cred *new, const struct cred *old) +{ + /* + * Since "struct tomoyo_domain_info *" is a sharable pointer, + * we don't need to duplicate. + */ + new->security = old->security; +} + static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) { int rc; @@ -262,7 +277,9 @@ static int tomoyo_dentry_open(struct file *f, const struct cred *cred) */ static struct security_operations tomoyo_security_ops = { .name = "tomoyo", + .cred_alloc_blank = tomoyo_cred_alloc_blank, .cred_prepare = tomoyo_cred_prepare, + .cred_transfer = tomoyo_cred_transfer, .bprm_set_creds = tomoyo_bprm_set_creds, .bprm_check_security = tomoyo_bprm_check_security, #ifdef CONFIG_SYSCTL -- cgit v1.2.3 From 1ee65e37e904b959c24404139f5752edc66319d5 Mon Sep 17 00:00:00 2001 From: "David P. Quigley" Date: Thu, 3 Sep 2009 14:25:57 -0400 Subject: LSM/SELinux: inode_{get,set,notify}secctx hooks to access LSM security context information. This patch introduces three new hooks. The inode_getsecctx hook is used to get all relevant information from an LSM about an inode. The inode_setsecctx is used to set both the in-core and on-disk state for the inode based on a context derived from inode_getsecctx.The final hook inode_notifysecctx will notify the LSM of a change for the in-core state of the inode in question. These hooks are for use in the labeled NFS code and addresses concerns of how to set security on an inode in a multi-xattr LSM. For historical reasons Stephen Smalley's explanation of the reason for these hooks is pasted below. Quote Stephen Smalley inode_setsecctx: Change the security context of an inode. Updates the in core security context managed by the security module and invokes the fs code as needed (via __vfs_setxattr_noperm) to update any backing xattrs that represent the context. Example usage: NFS server invokes this hook to change the security context in its incore inode and on the backing file system to a value provided by the client on a SETATTR operation. inode_notifysecctx: Notify the security module of what the security context of an inode should be. Initializes the incore security context managed by the security module for this inode. Example usage: NFS client invokes this hook to initialize the security context in its incore inode to the value provided by the server for the file when the server returned the file's attributes to the client. Signed-off-by: David P. Quigley Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++ security/capability.c | 17 ++++++++++++++ security/security.c | 18 +++++++++++++++ security/selinux/hooks.c | 29 ++++++++++++++++++++++++ security/smack/smack_lsm.c | 24 ++++++++++++++++++++ 5 files changed, 143 insertions(+) (limited to 'security/capability.c') diff --git a/include/linux/security.h b/include/linux/security.h index 10a09257952b..d050b66ab9ef 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1382,6 +1382,41 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * audit_rule_init. * @rule contains the allocated rule * + * @inode_notifysecctx: + * Notify the security module of what the security context of an inode + * should be. Initializes the incore security context managed by the + * security module for this inode. Example usage: NFS client invokes + * this hook to initialize the security context in its incore inode to the + * value provided by the server for the file when the server returned the + * file's attributes to the client. + * + * Must be called with inode->i_mutex locked. + * + * @inode we wish to set the security context of. + * @ctx contains the string which we wish to set in the inode. + * @ctxlen contains the length of @ctx. + * + * @inode_setsecctx: + * Change the security context of an inode. Updates the + * incore security context managed by the security module and invokes the + * fs code as needed (via __vfs_setxattr_noperm) to update any backing + * xattrs that represent the context. Example usage: NFS server invokes + * this hook to change the security context in its incore inode and on the + * backing filesystem to a value provided by the client on a SETATTR + * operation. + * + * Must be called with inode->i_mutex locked. + * + * @dentry contains the inode we wish to set the security context of. + * @ctx contains the string which we wish to set in the inode. + * @ctxlen contains the length of @ctx. + * + * @inode_getsecctx: + * Returns a string containing all relavent security context information + * + * @inode we wish to set the security context of. + * @ctx is a pointer in which to place the allocated security context. + * @ctxlen points to the place to put the length of @ctx. * This is the main security structure. */ struct security_operations { @@ -1590,6 +1625,10 @@ struct security_operations { int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid); void (*release_secctx) (char *secdata, u32 seclen); + int (*inode_notifysecctx)(struct inode *inode, void *ctx, u32 ctxlen); + int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen); + int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen); + #ifdef CONFIG_SECURITY_NETWORK int (*unix_stream_connect) (struct socket *sock, struct socket *other, struct sock *newsk); @@ -1839,6 +1878,9 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); void security_release_secctx(char *secdata, u32 seclen); +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); #else /* CONFIG_SECURITY */ struct security_mnt_opts { }; @@ -2595,6 +2637,19 @@ static inline int security_secctx_to_secid(const char *secdata, static inline void security_release_secctx(char *secdata, u32 seclen) { } + +static inline int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return -EOPNOTSUPP; +} +static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return -EOPNOTSUPP; +} +static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_SECURITY */ #ifdef CONFIG_SECURITY_NETWORK diff --git a/security/capability.c b/security/capability.c index 93a2ffe65905..fce07a7bc825 100644 --- a/security/capability.c +++ b/security/capability.c @@ -822,6 +822,20 @@ static void cap_release_secctx(char *secdata, u32 seclen) { } +static int cap_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return 0; +} + +static int cap_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return 0; +} + +static int cap_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + return 0; +} #ifdef CONFIG_KEYS static int cap_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) @@ -1032,6 +1046,9 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, secid_to_secctx); set_to_cap_if_null(ops, secctx_to_secid); set_to_cap_if_null(ops, release_secctx); + set_to_cap_if_null(ops, inode_notifysecctx); + set_to_cap_if_null(ops, inode_setsecctx); + set_to_cap_if_null(ops, inode_getsecctx); #ifdef CONFIG_SECURITY_NETWORK set_to_cap_if_null(ops, unix_stream_connect); set_to_cap_if_null(ops, unix_may_send); diff --git a/security/security.c b/security/security.c index d8b727637f02..c4c673240c1c 100644 --- a/security/security.c +++ b/security/security.c @@ -974,6 +974,24 @@ void security_release_secctx(char *secdata, u32 seclen) } EXPORT_SYMBOL(security_release_secctx); +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return security_ops->inode_notifysecctx(inode, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_notifysecctx); + +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return security_ops->inode_setsecctx(dentry, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_setsecctx); + +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + return security_ops->inode_getsecctx(inode, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_getsecctx); + #ifdef CONFIG_SECURITY_NETWORK int security_unix_stream_connect(struct socket *sock, struct socket *other, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 134a9c0d2004..7118be2a74a5 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5351,6 +5351,32 @@ static void selinux_release_secctx(char *secdata, u32 seclen) kfree(secdata); } +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); +} + +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); +} + +static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + int len = 0; + len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, + ctx, true); + if (len < 0) + return len; + *ctxlen = len; + return 0; +} #ifdef CONFIG_KEYS static int selinux_key_alloc(struct key *k, const struct cred *cred, @@ -5550,6 +5576,9 @@ static struct security_operations selinux_ops = { .secid_to_secctx = selinux_secid_to_secctx, .secctx_to_secid = selinux_secctx_to_secid, .release_secctx = selinux_release_secctx, + .inode_notifysecctx = selinux_inode_notifysecctx, + .inode_setsecctx = selinux_inode_setsecctx, + .inode_getsecctx = selinux_inode_getsecctx, .unix_stream_connect = selinux_socket_unix_stream_connect, .unix_may_send = selinux_socket_unix_may_send, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 969f5fee1906..0b3bb646f90e 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3057,6 +3057,27 @@ static void smack_release_secctx(char *secdata, u32 seclen) { } +static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); +} + +static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); +} + +static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + int len = 0; + len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); + + if (len < 0) + return len; + *ctxlen = len; + return 0; +} + struct security_operations smack_ops = { .name = "smack", @@ -3185,6 +3206,9 @@ struct security_operations smack_ops = { .secid_to_secctx = smack_secid_to_secctx, .secctx_to_secid = smack_secctx_to_secid, .release_secctx = smack_release_secctx, + .inode_notifysecctx = smack_inode_notifysecctx, + .inode_setsecctx = smack_inode_setsecctx, + .inode_getsecctx = smack_inode_getsecctx, }; -- cgit v1.2.3