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| author | Thomas Gleixner <tglx@linutronix.de> | 2014-09-11 23:44:35 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-11-05 20:27:43 +0000 |
| commit | 2e10b8a67f891a1d9b86ca72321259a7f63d3b42 (patch) | |
| tree | cff4d6f743386922c0ff0611eda19b0abdb71387 /kernel/futex.c | |
| parent | 29a8d1a41767ad86f7caca17762a7fddf3207201 (diff) | |
| download | kernel_samsung_smdk4412-2e10b8a67f891a1d9b86ca72321259a7f63d3b42.zip kernel_samsung_smdk4412-2e10b8a67f891a1d9b86ca72321259a7f63d3b42.tar.gz kernel_samsung_smdk4412-2e10b8a67f891a1d9b86ca72321259a7f63d3b42.tar.bz2 | |
futex: Unlock hb->lock in futex_wait_requeue_pi() error path
commit 13c42c2f43b19aab3195f2d357db00d1e885eaa8 upstream.
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>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1409112318500.4178@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.2: queue_unlock() takes two parameters]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'kernel/futex.c')
| -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 1bb37d0..f31f190 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2460,6 +2460,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * shared futexes. We need to compare the keys: */ if (match_futex(&q.key, &key2)) { + queue_unlock(&q, hb); ret = -EINVAL; goto out_put_keys; } |