CVE-2026-80816

What the bug is

fcp_init_notify() used mixer->urb, which snd_usb_mixer_status_create() allocates for the optional UAC2 status interrupt endpoint and mixer.c kills, resubmits and frees. On a device with that endpoint, fcp_init_notify()'s "already set up" early return fires on the status URB and returns success without doing anything. No FCP notification URB is submitted, and cmd_done is left zeroed because it is initialised past that early return and nowhere else. fcp_init() then issues init1_opcode and wait_for_completion_timeout() would crash adding to the zeroed wait.head. fcp_cleanup_urb() would also kill and free mixer.c's status URB. Use a separate URB in fcp_data, and initialise cmd_done in fcp_init_private() where fcp_data is allocated. fcp_init_notify() is reached again after suspend via fcp_reinit(), and the URB kill path in fcp_notify() completes cmd_done, leaving a stale count that would satisfy the next command's wait before the device ACKs. Use reinit_completion() to clear it.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

sound/usb/fcp.c

What this is

FOCUSRITE CONTROL PROTOCOL/SCARLETT2 MIXER DRIVERS (Scarlett Gen 2+, Clarett, and Vocaster)MAINTAINERS section matched on sound/usb/fcp.c · linux-sound@vger.kernel.org · Maintained

Kernel module

snd_usb_audio

Check it on the machine

grep -wE 'CONFIG_SND|CONFIG_SND_USB_AUDIO' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w snd_usb_audio

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64

?

not established - no Makefile entry for the affected file

M

a module where it is built at all; some flavours do not build it

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_SND, CONFIG_SND_USB_AUDIO

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.3% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

sound/usb

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.14	6.18.47	65aceb45ca91
6.14	7.1.11	5da21a434171
6.14	7.2.1	6db3c1d7e287
6.14	7.3	918b8d231c57