aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@tv-sign.ru>2007-08-22 14:01:37 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-22 19:52:46 -0700
commitd02479bdeb1c9b037892061cdcf4e730183391fa (patch)
tree1268f3dcf973f8fc3d86c84d9b09ff9048647491 /kernel
parent179394af7a2baa1d0a3cb1670075310d72247d38 (diff)
downloadlinux-linaro-d02479bdeb1c9b037892061cdcf4e730183391fa.tar.gz
posix-timers: fix creation race
sys_timer_create() sets ->it_process and unlocks ->siglock, then checks tmr->it_sigev_notify to define if get_task_struct() is needed. We already passed ->it_id to the caller, another thread can delete this timer and free its memory in between. As a minimal fix, move this code under ->siglock, sys_timer_delete() takes it too before calling release_posix_timer(). A proper serialization would be to take ->it_lock, we add a partly initialized timer on posix_timers_id, not good. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/posix-timers.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 6923ad8a598..7a15afb73ed 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -547,9 +547,9 @@ sys_timer_create(const clockid_t which_clock,
new_timer->it_process = process;
list_add(&new_timer->list,
&process->signal->posix_timers);
- spin_unlock_irqrestore(&process->sighand->siglock, flags);
if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
get_task_struct(process);
+ spin_unlock_irqrestore(&process->sighand->siglock, flags);
} else {
spin_unlock_irqrestore(&process->sighand->siglock, flags);
process = NULL;