This is a note to let you know that I've just added the patch titled futex: Drop refcount if requeue_pi() acquired the rtmutex to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: futex-drop-refcount-if-requeue_pi-acquired-the-rtmutex.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fb75a4282d0d9a3c7c44d940582c2d226cf3acfb Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Date: Sat, 19 Dec 2015 20:07:38 +0000 Subject: futex: Drop refcount if requeue_pi() acquired the rtmutex From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> 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 <tglx@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Darren Hart <darren@xxxxxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Cc: Bhuvanesh_Surachari@xxxxxxxxxx Cc: Andy Lowe <Andy_Lowe@xxxxxxxxxx> Link: http://lkml.kernel.org/r/20151219200607.178132067@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/futex.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2755,6 +2755,11 @@ static int futex_wait_requeue_pi(u32 __u 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 { Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are queue-4.4/itimers-handle-relative-timers-with-config_time_low_res-proper.patch queue-4.4/futex-drop-refcount-if-requeue_pi-acquired-the-rtmutex.patch queue-4.4/x86-mm-pat-avoid-truncation-when-converting-cpa-numpages-to-address.patch queue-4.4/x86-uaccess-64-handle-the-caching-of-4-byte-nocache-copies-properly-in-__copy_user_nocache.patch queue-4.4/timerfd-handle-relative-timers-with-config_time_low_res-proper.patch queue-4.4/posix-timers-handle-relative-timers-with-config_time_low_res-proper.patch queue-4.4/x86-mm-fix-vmalloc_fault-to-handle-large-pages-properly.patch queue-4.4/x86-mm-fix-types-used-in-pgprot-cacheability-flags-translations.patch queue-4.4/x86-uaccess-64-make-the-__copy_user_nocache-assembly-code-more-readable.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html