From: Chengfeng Ye Date: Sun, 24 Oct 2021 11:17:36 +0000 (-0700) Subject: ALSA: usb-audio: fix null pointer dereference on pointer cs_desc X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=58fa50de595f152900594c28ec9915c169643739;p=linux.git ALSA: usb-audio: fix null pointer dereference on pointer cs_desc [ 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 Link: https://lore.kernel.org/r/20211024111736.11342-1-cyeaa@connect.ust.hk Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- 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