[PATCH 1/3] futex: Test for pi_mutex on fault in futex_wait_requeue_pi

From: Darren Hart
Date: Fri Jul 20 2012 - 14:49:29 EST


If fixup_pi_state_owner() faults, pi_mutex may be NULL. Test
for pi_mutex != NULL before testing the owner against current
and possibly unlocking it.

Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx>
CC: Dave Jones <davej@xxxxxxxxxx>
CC: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/futex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index e2b0fb9..05018bf 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2370,7 +2370,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* fault, unlock the rt_mutex and return the fault to userspace.
*/
if (ret == -EFAULT) {
- if (rt_mutex_owner(pi_mutex) == current)
+ if (pi_mutex && rt_mutex_owner(pi_mutex) == current)
rt_mutex_unlock(pi_mutex);
} else if (ret == -EINTR) {
/*
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/