From 3c80fe4ac9cfb13b1bfa4edf1544e8b656716694 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 9 Dec 2009 14:19:31 +0000 Subject: audit: Call tty_audit_push_task() outside preempt disabled While auditing all tasklist_lock read_lock sites I stumbled over the following call chain: audit_prepare_user_tty() read_lock(&tasklist_lock); tty_audit_push_task(); mutex_lock(&buf->mutex); --> buf->mutex is locked with preemption disabled. Solve this by acquiring a reference to the task struct under rcu_read_lock and call tty_audit_push_task outside of the preempt disabled region. Move all code which needs to be protected by sighand lock into tty_audit_push_task() and use lock/unlock_sighand as we do not hold tasklist_lock. Signed-off-by: Thomas Gleixner Cc: Al Viro Cc: Eric Paris Cc: Oleg Nesterov Signed-off-by: Al Viro --- include/linux/tty.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/tty.h b/include/linux/tty.h index e500171c745f..2a754748dd5f 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -541,8 +541,8 @@ extern void tty_audit_exit(void); extern void tty_audit_fork(struct signal_struct *sig); extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); extern void tty_audit_push(struct tty_struct *tty); -extern void tty_audit_push_task(struct task_struct *tsk, - uid_t loginuid, u32 sessionid); +extern int tty_audit_push_task(struct task_struct *tsk, + uid_t loginuid, u32 sessionid); #else static inline void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, size_t size) @@ -560,9 +560,10 @@ static inline void tty_audit_fork(struct signal_struct *sig) static inline void tty_audit_push(struct tty_struct *tty) { } -static inline void tty_audit_push_task(struct task_struct *tsk, - uid_t loginuid, u32 sessionid) +static inline int tty_audit_push_task(struct task_struct *tsk, + uid_t loginuid, u32 sessionid) { + return 0; } #endif -- cgit v1.2.2