diff options
| author | Kees Cook <keescook@chromium.org> | 2011-12-21 12:17:03 -0800 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2012-02-10 09:14:51 +1100 |
| commit | 1a2a4d06e1e95260c470ebe3a945f61bbe8c1fd8 (patch) | |
| tree | 7167d158749a7acf2ce8bbe1ecd25234b654e813 | |
| parent | 9e3ff38647a316e4f92d59b14c8f0eb13b33bb2c (diff) | |
security: create task_free security callback
The current LSM interface to cred_free is not sufficient for allowing
an LSM to track the life and death of a task. This patch adds the
task_free hook so that an LSM can clean up resources on task death.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <jmorris@namei.org>
| -rw-r--r-- | include/linux/security.h | 9 | ||||
| -rw-r--r-- | kernel/fork.c | 1 | ||||
| -rw-r--r-- | security/capability.c | 5 | ||||
| -rw-r--r-- | security/security.c | 5 |
4 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/security.h b/include/linux/security.h index 83c18e8c846d..8325eddd9ee4 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -651,6 +651,10 @@ 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. + * @task_free: + * @task task being freed + * Handle release of task-related resources. (Note that this can be called + * from interrupt context.) * @cred_alloc_blank: * @cred points to the credentials. * @gfp indicates the atomicity of any memory allocations. @@ -1493,6 +1497,7 @@ struct security_operations { int (*dentry_open) (struct file *file, const struct cred *cred); int (*task_create) (unsigned long clone_flags); + void (*task_free) (struct task_struct *task); 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, @@ -1752,6 +1757,7 @@ 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); +void security_task_free(struct task_struct *task); 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); @@ -2245,6 +2251,9 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } +static inline void security_task_free(struct task_struct *task) +{ } + static inline int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { return 0; diff --git a/kernel/fork.c b/kernel/fork.c index 1b2ef3c23ae4..f0e7781ba9b4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -192,6 +192,7 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); + security_task_free(tsk); exit_creds(tsk); delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); diff --git a/security/capability.c b/security/capability.c index 2f680eb02b59..5bb21b1c448c 100644 --- a/security/capability.c +++ b/security/capability.c @@ -358,6 +358,10 @@ static int cap_task_create(unsigned long clone_flags) return 0; } +static void cap_task_free(struct task_struct *task) +{ +} + static int cap_cred_alloc_blank(struct cred *cred, gfp_t gfp) { return 0; @@ -954,6 +958,7 @@ void __init 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, task_free); 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); diff --git a/security/security.c b/security/security.c index d7542493454d..7d9426bb7442 100644 --- a/security/security.c +++ b/security/security.c @@ -729,6 +729,11 @@ int security_task_create(unsigned long clone_flags) return security_ops->task_create(clone_flags); } +void security_task_free(struct task_struct *task) +{ + security_ops->task_free(task); +} + int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { return security_ops->cred_alloc_blank(cred, gfp); |