Patch "ALSA: seq: Remove spurious WARN_ON() at timer check" has been added to the 3.18-stable tree

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

ALSA: seq: Remove spurious WARN_ON() at timer check

to the 3.18-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:
alsa-seq-remove-spurious-warn_on-at-timer-check.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Takashi Iwai <[email protected]>
Date: Thu, 30 Nov 2017 10:08:28 +0100
Subject: ALSA: seq: Remove spurious WARN_ON() at timer check

From: Takashi Iwai <[email protected]>

commit 43a3542870328601be02fcc9d27b09db467336ef upstream.

The use of snd_BUG_ON() in ALSA sequencer timer may lead to a spurious WARN_ON() when a slave timer is deployed as its backend and a corresponding master timer stops meanwhile. The symptom was triggered by syzkaller spontaneously.

Since the NULL timer is valid there, rip off snd_BUG_ON().

---
 sound/core/seq/seq_timer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -355,7 +355,7 @@ static int initialize_timer(struct snd_s
 	unsigned long freq;
 
 	t = tmr->timeri->timer;
-	if (snd_BUG_ON(!t))
+	if (!t)
 		return -EINVAL;
 
 	freq = tmr->preferred_resolution;

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/alsa-seq-remove-spurious-warn_on-at-timer-check.patch queue-3.18/alsa-pcm-prevent-uaf-in-snd_pcm_info.patch queue-3.18/alsa-usb-audio-add-check-return-value-for-usb_string.patch queue-3.18/alsa-usb-audio-fix-out-of-bound-error.patch