CVE-2026-80642

What the bug is

Increment the incoming FLB refcount in liveupdate_flb_get_incoming() so that the FLB structure cannot be freed while the caller is actively using it. Add an additional liveupdate_flb_put_incoming() function so the caller can explicitly indicate when it is done using the FLB data. During a Live Update, a subsystem might need to hold onto the incoming File-Lifecycle-Bound (FLB) data for an extended period, such as during device enumeration. Incrementing the reference count guarantees that the data remains valid and accessible until the subsystem releases it, preventing future use-after-free bugs.

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.

include/linux/liveupdate.h
kernel/liveupdate/luo_flb.c
lib/tests/liveupdate.c

What this is

LIVE UPDATEMAINTAINERS section matched on include/linux/liveupdate.h · kexec@lists.infradead.org · Maintained

Check it on the machine

grep -w CONFIG_LIVEUPDATE /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 2 releases. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidn

?

not established - no Makefile entry for the affected file

n

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

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 switch

CONFIG_LIVEUPDATE

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

2026-08-28 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.20%, higher than 8.9% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

include/linux

Upstream fixes

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

Introduced	Fixed in	Commit
7.0	7.1.5	725ada0273a0
7.0	7.2	d8e47bd066d7