This is a note to let you know that I've just added the patch titled ALSA: mixer: fix deadlock in snd_mixer_oss_set_volume 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: alsa-mixer-fix-deadlock-in-snd_mixer_oss_set_volume.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 3ab7992018455ac63c33e9b3eaa7264e293e40f4 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin <paskripkin@xxxxxxxxx> Date: Sun, 24 Oct 2021 17:03:15 +0300 Subject: ALSA: mixer: fix deadlock in snd_mixer_oss_set_volume From: Pavel Skripkin <paskripkin@xxxxxxxxx> commit 3ab7992018455ac63c33e9b3eaa7264e293e40f4 upstream. In commit 411cef6adfb3 ("ALSA: mixer: oss: Fix racy access to slots") added mutex protection in snd_mixer_oss_set_volume(). Second mutex_lock() in same function looks like typo, fix it. Reported-by: syzbot+ace149a75a9a0a399ac7@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 411cef6adfb3 ("ALSA: mixer: oss: Fix racy access to slots") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx> Link: https://lore.kernel.org/r/20211024140315.16704-1-paskripkin@xxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/core/oss/mixer_oss.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/core/oss/mixer_oss.c +++ b/sound/core/oss/mixer_oss.c @@ -327,7 +327,7 @@ static int snd_mixer_oss_set_volume(stru pslot->volume[1] = right; result = (left & 0xff) | ((right & 0xff) << 8); unlock: - mutex_lock(&mixer->reg_mutex); + mutex_unlock(&mixer->reg_mutex); return result; } Patches currently in stable-queue which might be from paskripkin@xxxxxxxxx are queue-4.4/alsa-mixer-fix-deadlock-in-snd_mixer_oss_set_volume.patch