CVE-2026-89871

What the bug is

kthread_run() returns an ERR_PTR on failure, not NULL. When start_streaming() fails, data->kthread_vid_cap is left holding this error pointer instead of being cleared. This causes two subsequent bugs: 1. A future call to start_streaming() sees a non-NULL kthread_vid_cap and returns 0 (success) immediately, without actually starting the capture thread. 2. A call to stop_streaming() checks 'kthread_vid_cap == NULL' which is false for an error pointer, and proceeds to call kthread_stop() on the error pointer, leading to a kernel crash. Fix this by resetting kthread_vid_cap to NULL on failure before jumping to the error path.

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.

drivers/media/i2c/video-i2c.c

What this is

VIDEO I2C POLLING DRIVERMAINTAINERS section matched on drivers/media/i2c/video-i2c.c · linux-media@vger.kernel.org · Maintained

Kernel module

none to look for. The file would have gone into video_i2c, and Debian does not compile it into that module, so finding video_i2c in lsmod would say nothing about this CVE.

Check it on the machine

grep -w CONFIG_VIDEO_I2C /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.

Show whether Debian builds this, per release

Debian does not build this code. In 5 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sid, bookworm · linux-6.12n

n

not enabled on any flavour - this release does not build the code

Build switch

CONFIG_VIDEO_I2C

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

2026-09-16 (33 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/media

Upstream fixes

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

Introduced	Fixed in	Commit
4.18	5.10.270	db0f4531aa55
4.18	5.15.221	0fac63cac668
4.18	6.1.188	5c35d380bea6
4.18	6.6.157	3d1b10d81fe5
4.18	6.12.110	968c5213e34c
4.18	6.18.51	52fd9d80c0ce
4.18	7.2.5	0e7f2cd72a4f
4.18	7.3	76e379754ba6

Debian advisories