CVE-2026-92483

What the bug is

LUO keeps track of successful retrieve attempts on an FLB. It does so to avoid multiple retrievals of the same FLB. Multiple retrievals cause problems because once the FLB is retrieved, the serialized data structures are likely freed and the FLB is likely in a very different state from what the code expects. All this works well when retrieve succeeds. When it fails, luo_flb_retrieve_one() returns the error immediately, without ever storing anywhere that a retrieve was attempted or what its error code was. If the user attempts to retrieve another file registered with the same FLB, LUO will attempt to call the FLB's retrieve() callback again. The retry is problematic for much of the same reasons listed above. The FLB is likely in a very different state than what the retrieve logic normally expects (e.g. some KHO pages may have already been restored and freed). There is no sane way of attempting the retrieve again. Remember the error retrieve returned and directly return it on a retry. This is done by changing the retrieved bool to a retrieve_status integer. A value of 0 means retrieve was never attempted, a positive value means it succeeded, and a negative value means it failed and the error code is the value. This is similar to commit f85b1c6af5bc ("liveupdate: luo_file: remember retrieve() status") which did the same for LUO files.

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

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

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.22%, higher than 11.6% 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	7.2.6	908f3ea3f050
7.0	7.3	5c4a03afcb21