This is a note to let you know that I've just added the patch titled

workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: workqueue-trigger-warn-if-queue_delayed_work-is-called-with-null-wq.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@vger.kernel.org know about it.

From foo@baz Tue Dec 12 13:38:50 CET 2017

From: Tejun Heo tj@kernel.org Date: Mon, 6 Mar 2017 15:33:42 -0500 Subject: workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq

From: Tejun Heo tj@kernel.org

[ Upstream commit 637fdbae60d6cb9f6e963c1079d7e0445c86ff7d ]

If queue_delayed_work() gets called with NULL @wq, the kernel will oops asynchronuosly on timer expiration which isn't too helpful in tracking down the offender. This actually happened with smc.

__queue_delayed_work() already does several input sanity checks synchronously. Add NULL @wq check.

Reported-by: Dave Jones davej@codemonkey.org.uk Link: http://lkml.kernel.org/r/20170227171439.jshx3qplflyrgcv7@codemonkey.org.uk Signed-off-by: Tejun Heo tj@kernel.org Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/workqueue.c | 1 + 1 file changed, 1 insertion(+)

--- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1479,6 +1479,7 @@ static void __queue_delayed_work(int cpu struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work;

+ WARN_ON_ONCE(!wq); WARN_ON_ONCE(timer->function != delayed_work_timer_fn || timer->data != (unsigned long)dwork); WARN_ON_ONCE(timer_pending(timer));

Patches currently in stable-queue which might be from tj@kernel.org are

queue-4.4/libata-drop-warn-from-protocol-error-in-ata_sff_qc_issue.patch queue-4.4/workqueue-trigger-warn-if-queue_delayed_work-is-called-with-null-wq.patch