From: Chengfeng Ye cyeaa@connect.ust.hk

[ Upstream commit b97053df0f04747c3c1e021ecbe99db675342954 ]

The pointer cs_desc return from snd_usb_find_clock_source could be null, so there is a potential null pointer dereference issue. Fix this by adding a null check before dereference.

Signed-off-by: Chengfeng Ye cyeaa@connect.ust.hk Link: https://lore.kernel.org/r/20211024111736.11342-1-cyeaa@connect.ust.hk Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/clock.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 81d5ce07d548b..98345a695dccb 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -496,6 +496,10 @@ int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip, union uac23_clock_source_desc *cs_desc;

cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol); + + if (!cs_desc) + return 0; + if (fmt->protocol == UAC_VERSION_3) bmControls = le32_to_cpu(cs_desc->v3.bmControls); else