DivestOS/Patches/Linux_CVEs/CVE-2016-2544/ANY/0.patch

39 lines
1.3 KiB
Diff
Raw Normal View History

From 3567eb6af614dac436c4b16a8d426f9faed639b3 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 12 Jan 2016 15:36:27 +0100
Subject: ALSA: seq: Fix race at timer setup and close
ALSA sequencer code has an open race between the timer setup ioctl and
the close of the client. This was triggered by syzkaller fuzzer, and
a use-after-free was caught there as a result.
This patch papers over it by adding a proper queue->timer_mutex lock
around the timer-related calls in the relevant code path.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/core/seq/seq_queue.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/core/seq/seq_queue.c b/sound/core/seq/seq_queue.c
index 7dfd0f4..0bec02e 100644
--- a/sound/core/seq/seq_queue.c
+++ b/sound/core/seq/seq_queue.c
@@ -142,8 +142,10 @@ static struct snd_seq_queue *queue_new(int owner, int locked)
static void queue_delete(struct snd_seq_queue *q)
{
/* stop and release the timer */
+ mutex_lock(&q->timer_mutex);
snd_seq_timer_stop(q->timer);
snd_seq_timer_close(q);
+ mutex_unlock(&q->timer_mutex);
/* wait until access free */
snd_use_lock_sync(&q->use_lock);
/* release resources... */
--
cgit v1.1