This is a note to let you know that I've just added the patch titled
posix-cpu-timers: Fix nanosleep task_struct leak
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
posix-cpu-timers-fix-nanosleep-task_struct-leak.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From e6c42c295e071dd74a66b5a9fcf4f44049888ed8 Mon Sep 17 00:00:00 2001
From: Stanislaw Gruszka <[email protected]>
Date: Fri, 15 Feb 2013 11:08:11 +0100
Subject: posix-cpu-timers: Fix nanosleep task_struct leak
From: Stanislaw Gruszka <[email protected]>
commit e6c42c295e071dd74a66b5a9fcf4f44049888ed8 upstream.
The trinity fuzzer triggered a task_struct reference leak via
clock_nanosleep with CPU_TIMERs. do_cpu_nanosleep() calls
posic_cpu_timer_create(), but misses a corresponding
posix_cpu_timer_del() which leads to the task_struct reference leak.
Reported-and-tested-by: Tommi Rantala <[email protected]>
Signed-off-by: Stanislaw Gruszka <[email protected]>
Cc: Dave Jones <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/posix-cpu-timers.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1450,8 +1450,10 @@ static int do_cpu_nanosleep(const clocki
while (!signal_pending(current)) {
if (timer.it.cpu.expires.sched == 0) {
/*
- * Our timer fired and was reset.
+ * Our timer fired and was reset, below
+ * deletion can not fail.
*/
+ posix_cpu_timer_del(&timer);
spin_unlock_irq(&timer.it_lock);
return 0;
}
@@ -1469,9 +1471,26 @@ static int do_cpu_nanosleep(const clocki
* We were interrupted by a signal.
*/
sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
- posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ if (!error) {
+ /*
+ * Timer is now unarmed, deletion can not fail.
+ */
+ posix_cpu_timer_del(&timer);
+ }
spin_unlock_irq(&timer.it_lock);
+ while (error == TIMER_RETRY) {
+ /*
+ * We need to handle case when timer was or is in the
+ * middle of firing. In other cases we already freed
+ * resources.
+ */
+ spin_lock_irq(&timer.it_lock);
+ error = posix_cpu_timer_del(&timer);
+ spin_unlock_irq(&timer.it_lock);
+ }
+
if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
/*
* It actually did fire already.
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/posix-cpu-timers-fix-nanosleep-task_struct-leak.patch
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