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[3.13.y-ckt,stable] Patch "ALSA: timer: Fix double unlink of active_list" has been added to the 3.13.y-ckt tree

Message ID 1454373365-4738-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Feb. 2, 2016, 12:36 a.m. UTC
This is a note to let you know that I have just added a patch titled

    ALSA: timer: Fix double unlink of active_list

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt34.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

From be1ebfffaffdca241958d338ddafe89ecd241e41 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 13 Jan 2016 21:35:06 +0100
Subject: ALSA: timer: Fix double unlink of active_list

commit ee8413b01045c74340aa13ad5bdf905de32be736 upstream.

ALSA timer instance object has a couple of linked lists and they are
unlinked unconditionally at snd_timer_stop().  Meanwhile
snd_timer_interrupt() unlinks it, but it calls list_del() which leaves
the element list itself unchanged.  This ends up with unlinking twice,
and it was caught by syzkaller fuzzer.

The fix is to use list_del_init() variant properly there, too.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 sound/core/timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--
1.9.1
diff mbox

Patch

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 6ddcf06..3bd05d9 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -693,7 +693,7 @@  void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 		} else {
 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 			if (--timer->running)
-				list_del(&ti->active_list);
+				list_del_init(&ti->active_list);
 		}
 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))