Commit-ID: e6c42c295e071dd74a66b5a9fcf4f44049888ed8 Gitweb: http://git.kernel.org/tip/e6c42c295e071dd74a66b5a9fcf4f44049888ed8 Author: Stanislaw Gruszka <sgrus...@redhat.com> AuthorDate: Fri, 15 Feb 2013 11:08:11 +0100 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 15 Feb 2013 11:41:56 +0100
posix-cpu-timers: Fix nanosleep task_struct leak 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 <tt.rant...@gmail.com> Signed-off-by: Stanislaw Gruszka <sgrus...@redhat.com> Cc: Dave Jones <da...@redhat.com> Cc: John Stultz <john.stu...@linaro.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: sta...@vger.kernel.org Link: http://lkml.kernel.org/r/20130215100810.gf4...@redhat.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
