ALSA: timer: Fix wrong instance passed to slave callbacks

commit 117159f0b9 upstream.

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@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Iwai
2016-02-08 17:36:25 +01:00
committed by Greg Kroah-Hartman
parent 925249d517
commit 4333cce1e7

View File

@@ -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);
}