From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758921Ab3BGQEo (ORCPT ); Thu, 7 Feb 2013 11:04:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16529 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757499Ab3BGQEk (ORCPT ); Thu, 7 Feb 2013 11:04:40 -0500 Date: Thu, 7 Feb 2013 17:04:27 +0100 From: Stanislaw Gruszka To: Oleg Nesterov , Thomas Gleixner Cc: LKML , Dave Jones , John Stultz , Tommi Rantala Subject: [PATCH v2] posix-cpu-timers: fix nanosleep task_struct leak Message-ID: <20130207160427.GA6189@redhat.com> References: <20130204193223.GA11910@redhat.com> <20130205103455.GB18313@redhat.com> <20130206112327.GA1824@redhat.com> <20130206151550.GA1758@redhat.com> <20130206161011.GA11161@redhat.com> <20130207122212.GA2668@redhat.com> <20130207132455.GA25793@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130207132455.GA25793@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In do_cpu_nanosleep() we do posic_cpu_timer_create(), but forgot corresponding posix_cpu_timer_del() what lead to task_struct leak. Reported-and-tested-by: Tommi Rantala Signed-off-by: Stanislaw Gruszka --- v1 -> v2: add comments kernel/posix-cpu-timers.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index a278cad..942ca27 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1401,8 +1401,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, 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; } @@ -1420,9 +1422,26 @@ 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) { + /* + * 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. -- 1.7.11.7