linux-kernel - [PATCH] posix-cpu-timers: fix nanosleep task

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Date:	Wed, 6 Feb 2013 16:15:51 +0100
From:	Stanislaw Gruszka <sgruszka@...hat.com>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	Oleg Nesterov <oleg@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Dave Jones <davej@...hat.com>,
	John Stultz <john.stultz@...aro.org>,
	Tommi Rantala <tt.rantala@...il.com>
Subject: [PATCH] posix-cpu-timers: fix nanosleep task_struct leak

In do_cpu_nanosleep() we do posix_cpu_timer_create(), but forgot
corresponding posix_cpu_timer_del(), what lead to task_struct leak.

Reported-and-tested-by: Tommi Rantala <tt.rantala@...il.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@...hat.com>
---
 kernel/posix-cpu-timers.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index a278cad..a01caac 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1403,6 +1403,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 				/*
 				 * Our timer fired and was reset.
 				 */
+				posix_cpu_timer_del(&timer);
 				spin_unlock_irq(&timer.it_lock);
 				return 0;
 			}
@@ -1420,9 +1421,17 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		 * 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)
+			posix_cpu_timer_del(&timer);
 		spin_unlock_irq(&timer.it_lock);
 
+		while (error == TIMER_RETRY) {
+			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.
-- 
1.7.11.7

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