This is a note to let you know that I've just added the patch titled ALSA: usb-audio: fix null pointer dereference on pointer cs_desc to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: alsa-usb-audio-fix-null-pointer-dereference-on-point.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit cf2536e79d3ed64ec8276f43e49fa862f510153f Author: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx> Date: Sun Oct 24 04:17:36 2021 -0700 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 <cyeaa@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211024111736.11342-1-cyeaa@xxxxxxxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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