snd_usb_mixer_controls_badd() that parses UAC3 BADD profiles misses a
NULL check for the given interfaces. When a malformed USB descriptor
is passed, this may lead to an Oops, as spotted by syzkaller.
Skip the iteration if the interface doesn't exist for avoiding the
crash.
Fixes: 17156f23e93c ("ALSA: usb: add UAC3 BADD profiles support")
Reported-by: syzbot+a36ab65c6653d7ccdd62@xxxxxxxxxxxxxxxxxxxxxxxxx
Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/usb/mixer.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 45eee5cc312e..6cd4ff09c5ee 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2930,6 +2930,9 @@ static int snd_usb_mixer_controls_badd(struct usb_mixer_interface *mixer,
continue;
iface = usb_ifnum_to_if(dev, intf);
+ if (!iface)
+ continue;
+
num = iface->num_altsetting;
if (num < 2)
--
2.16.4
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
