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| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2013-02-15 11:08:11 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2013-02-15 11:41:56 +0100 |
| commit | e6c42c295e071dd74a66b5a9fcf4f44049888ed8 (patch) | |
| tree | 7d417f64b7fa04511b4006eb4907ef41b7e401ed /kernel/posix-cpu-timers.c | |
| parent | 9f4646d28362bc424b8a4c7d09ea1c2f1759371a (diff) | |
| download | lwn-e6c42c295e071dd74a66b5a9fcf4f44049888ed8.tar.gz lwn-e6c42c295e071dd74a66b5a9fcf4f44049888ed8.zip | |
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.rantala@gmail.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20130215100810.GF4392@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/posix-cpu-timers.c')
| -rw-r--r-- | kernel/posix-cpu-timers.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index a278cad1d5d6..942ca27a28b7 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. |