From: Dongxiang Ke kdx.glider@gmail.com

[ Upstream commit e53f47f6c1a56d2af728909f1cb894da6b43d9bf ]

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 Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/stream.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/stream.c b/sound/usb/stream.c index ceb93d798182c..40ce8a1cb318a 100644 --- a/sound/usb/stream.c +++ b/sound/usb/stream.c @@ -1105,7 +1105,7 @@ 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++) {