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| author | Takashi Iwai <tiwai@suse.de> | 2016-01-13 21:35:06 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-31 11:23:33 -0800 |
| commit | dc5697eb3297920e20b53fdf4c40891e1ed0eafd (patch) | |
| tree | 435bec481989dea42dccb1e17d2edb426ef04ac3 | |
| parent | ac905ca58370789645e813d8abfa5871c93e9e36 (diff) | |
| download | lwn-dc5697eb3297920e20b53fdf4c40891e1ed0eafd.tar.gz lwn-dc5697eb3297920e20b53fdf4c40891e1ed0eafd.zip | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | sound/core/timer.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c index f5ec1ba4c4bb..3d2ba526093a 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -704,7 +704,7 @@ 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)) |