3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------ From: Thomas Gleixner <t...@linutronix.de> commit fb75a4282d0d9a3c7c44d940582c2d226cf3acfb upstream. If the proxy lock in the requeue loop acquires the rtmutex for a waiter then it acquired also refcount on the pi_state related to the futex, but the waiter side does not drop the reference count. Add the missing free_pi_state() call. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Darren Hart <dar...@dvhart.com> Cc: Davidlohr Bueso <d...@stgolabs.net> Cc: bhuvanesh_surach...@mentor.com Cc: Andy Lowe <andy_l...@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.178132...@linutronix.de Signed-off-by: Thomas Gleixner <t...@linutronix.de> Signed-off-by: Luis Henriques <luis.henriq...@canonical.com> --- kernel/futex.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/futex.c b/kernel/futex.c index 9fba3c706e2b..12b5f5264328 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2662,6 +2662,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, if (q.pi_state && (q.pi_state->owner != current)) { spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); + /* + * Drop the reference to the pi state which + * the requeue_pi() code acquired for us. + */ + free_pi_state(q.pi_state); spin_unlock(q.lock_ptr); } } else {
