[PATCH 1/2] ALSA: timer: Fix wrong instance passed to slave callbacks

[Takashi Iwai]

In snd_timer_notify1(), the wrong timer instance was passed for slave
ccallback function.  This leads to the access to the wrong data when
an incompatible master is handled (e.g. the master is the sequencer
timer and the slave is a user timer), as spotted by syzkaller fuzzer.

This patch fixes that wrong assignment.

BugLink: http://lkml.kernel.org/r/CACT4Y+Y_Bm+7epAb=8Wi=AaWd+DYS7qawX52qxdCfOfY49vozQ@xxxxxxxxxxxxxx
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
 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 9b513a05765a..dea932ac6165 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -422,7 +422,7 @@ static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 	spin_lock_irqsave(&timer->lock, flags);
 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
 		if (ts->ccallback)
-			ts->ccallback(ti, event + 100, &tstamp, resolution);
+			ts->ccallback(ts, event + 100, &tstamp, resolution);
 	spin_unlock_irqrestore(&timer->lock, flags);
 }
 
-- 
2.7.1


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