From 3c0e535fee2e67d06220e676cbf7b69099d741ce Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 13 Jan 2016 21:35:06 +0100 Subject: [PATCH] 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 Tested-by: Dmitry Vyukov Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/core/timer.c b/sound/core/timer.c index b0458285723a..4e8d7bfffff6 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)) -- 2.11.0