ALSA: timer: Fix leak in events via snd_timer_user_tinterrupt

The stack object “r1” has a total size of 32 bytes. Its field
“event” and “val” 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>
Orabug: 25059885
CVE: CVE-2016-4578
Mainline v4.7 commit e4ec8cc8039a7063e24204299b462bd1383184a5
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>

diff --git a/sound/core/timer.c b/sound/core/timer.c
index c85abca92ece3b70e5957476a0278021fe977dfc..7964203984edbdf53a691663b96de9dae037a109 100644 (file)
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1206,6 +1206,7 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
        }
        if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
            tu->last_resolution != resolution) {
+               memset(&r1, 0, sizeof(r1));
                r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
                r1.tstamp = tstamp;
                r1.val = resolution;