ALSA: usb-audio: Fix an out-of-bounds bug in __snd_usb_parse_audio_interface()

There may be a bad USB audio device with a USB ID of (0x04fa, 0x4201) and
the number of it's interfaces less than 4, an out-of-bounds read bug occurs
when parsing the interface descriptor for this device.

Fix this by checking the number of interfaces.

Signed-off-by: Dongxiang Ke <kdx.glider@gmail.com>
Link: https://lore.kernel.org/r/20220906024928.10951-1-kdx.glider@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Dongxiang Ke 2022-09-06 10:49:28 +08:00 committed by Takashi Iwai
parent 8d44e6044a
commit e53f47f6c1

View file

@ -1106,7 +1106,7 @@ static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
* Dallas DS4201 workaround: It presents 5 altsettings, but the last
* one misses syncpipe, and does not produce any sound.
*/
if (chip->usb_id == USB_ID(0x04fa, 0x4201))
if (chip->usb_id == USB_ID(0x04fa, 0x4201) && num >= 4)
num = 4;
for (i = 0; i < num; i++) {