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| author | Takashi Iwai <tiwai@suse.de> | 2019-11-22 14:28:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-01 11:17:38 +0300 |
| commit | 3510fb7947d5a7ca662178efe4f8d3712bb85177 (patch) | |
| tree | 427b98733ea4737528e6ab099399eef252719e8d /sound | |
| parent | 2819f4030f43057238992a4adcd950d7c95aff65 (diff) | |
| download | linux-3510fb7947d5a7ca662178efe4f8d3712bb85177.tar.xz | |
ALSA: usb-audio: Fix NULL dereference at parsing BADD
commit 9435f2bb66874a0c4dd25e7c978957a7ca2c93b1 upstream.
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@syzkaller.appspotmail.com
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191122112840.24797-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/mixer.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 726cbd63a0c7..d7778f2bcbf8 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2949,6 +2949,9 @@ 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) |