| Message ID | 1454029622-9006-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/kernel/futex.c b/kernel/futex.c index 63678b5..1c43013 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2632,6 +2632,11 @@ 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 {
This is a note to let you know that I have just added a patch titled futex: Drop refcount if requeue_pi() acquired the rtmutex to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt14. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 2bde82ca6a6fdb5b2a0c921e1df72f290f673395 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Sat, 19 Dec 2015 20:07:38 +0000 Subject: futex: Drop refcount if requeue_pi() acquired the rtmutex 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@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.178132067@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/futex.c | 5 +++++ 1 file changed, 5 insertions(+) -- 1.9.1