diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-09-11 23:44:35 +0200 |
|---|---|---|
| committer | Stefan Bader <stefan.bader@canonical.com> | 2014-11-25 15:20:28 +0100 |
| commit | eeb81c91a1b74fff798128faee60d54f086cfdd0 (patch) | |
| tree | bd43eb77ce7c5f1c3489629c4711ed4f548f9faa | |
| parent | 19a09028f13afb4367532d456401964f728ed115 (diff) | |
| download | linux-2.6.32.y-drm33.z-eeb81c91a1b74fff798128faee60d54f086cfdd0.tar.gz | |
futex: Unlock hb->lock in futex_wait_requeue_pi() error path
futex_wait_requeue_pi() calls futex_wait_setup(). If
futex_wait_setup() succeeds it returns with hb->lock held and
preemption disabled. Now the sanity check after this does:
if (match_futex(&q.key, &key2)) {
ret = -EINVAL;
goto out_put_keys;
}
which releases the keys but does not release hb->lock.
So we happily return to user space with hb->lock held and therefor
preemption disabled.
Unlock hb->lock before taking the exit route.
Reported-by: Dave "Trinity" Jones <davej@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1409112318500.4178@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
(cherry picked from commit 13c42c2f43b19aab3195f2d357db00d1e885eaa8)
[wt: 2.6.32 needs &q as first argument of queue_unlock()]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
| -rw-r--r-- | kernel/futex.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 55dd3d21f4c1f5..1e092d3465c164 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2414,6 +2414,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared, * shared futexes. We need to compare the keys: */ if (match_futex(&q.key, &key2)) { + queue_unlock(&q, hb); ret = -EINVAL; goto out_put_keys; } |