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. Fixes: 9ec73005 ("ALSA: usb-audio: Refactoring UAC2/3 clock setup code") Signed-off-by: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx> --- sound/usb/clock.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 81d5ce07d548..98345a695dcc 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 -- 2.17.1