ALSA: timer: Fix leak in events via snd_timer_user_ccallback

commit 9a47e9cff994f37f7f0dbd9ae23740d0f64f9fe6 upstream.

The stack object â\80\9cr1â\80\9d has a total size of 32 bytes. Its field
â\80\9ceventâ\80\9d and â\80\9cvalâ\80\9d both contain 4 bytes padding. These 8 bytes
padding bytes are sent to user without being initialized.

Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
[sw0312.kim: cherry-pick from linux-3.10.y to fix CVE-2016-4578]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I5bc3fef1419fe9bc9daa975ba89fd252d50591bf

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 8c3871b..1c340e7 100644 (file)
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1184,6 +1184,7 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
                tu->tstamp = *tstamp;
        if ((tu->filter & (1 << event)) == 0 || !tu->tread)
                return;
+       memset(&r1, 0, sizeof(r1));
        r1.event = event;
        r1.tstamp = *tstamp;
        r1.val = resolution;