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authorDarren Hart <dvhltc@us.ibm.com>2009-10-14 10:12:39 -0700
committerThomas Gleixner <tglx@linutronix.de>2009-10-14 22:00:14 +0200
commit2bc872036e1c5948b5b02942810bbdd8dbdb9812 (patch)
treec91cc2791366214c5f924ff5aa77c24a7403fe40
parentd58e6576b0deec6f0b9ff8450fe282da18c50883 (diff)
futex: Check for NULL keys in match_futex
If userspace tries to perform a requeue_pi on a non-requeue_pi waiter, it will find the futex_q->requeue_pi_key to be NULL and OOPS. Check for NULL in match_futex() instead of doing explicit NULL pointer checks on all call sites. While match_futex(NULL, NULL) returning false is a little odd, it's still correct as we expect valid key references. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Dinakar Guniguntala <dino@in.ibm.com> CC: John Stultz <johnstul@us.ibm.com> Cc: stable@kernel.org LKML-Reference: <4AD60687.10306@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/futex.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index 5c88839bd99..06938e560ac 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -150,7 +150,8 @@ static struct futex_hash_bucket *hash_futex(union futex_key *key)
*/
static inline int match_futex(union futex_key *key1, union futex_key *key2)
{
- return (key1->both.word == key2->both.word
+ return (key1 && key2
+ && key1->both.word == key2->both.word
&& key1->both.ptr == key2->both.ptr
&& key1->both.offset == key2->both.offset);
}