CVE-2026-97521

What the bug is

gfs2_quota_init() checks for duplicate quota_change IDs while holding qd_lock and the quota hash bucket bitlock. That path used gfs2_qd_search_bucket(), which takes a lockref reference via lockref_get_not_dead(). On PREEMPT_RT this may sleep, which is not allowed under the bucket bitlock, triggering "sleeping function called from invalid context". Use a no-ref bucket lookup in this path, then continue duplicate handling without taking a lockref there. Refactor gfs2_qd_search_bucket() to build on top of the no-ref helper so lookup traversal stays in one place. This patch fixes a bug reported by syzbot.

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.

fs/gfs2/quota.c

What this is

GFS2 FILE SYSTEMMAINTAINERS section matched on fs/gfs2/ · gfs2@lists.linux.dev · Supported

Kernel module

gfs2

Check it on the machine

grep -w CONFIG_GFS2_FS /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 gfs2

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.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

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

Build switch

CONFIG_GFS2_FS

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

2026-09-24 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.15%, higher than 4.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

fs/gfs2

Upstream fixes

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

Introduced	Fixed in	Commit
6.11	6.12.111	7fdcf16e5e14
6.11	6.18.53	812a766e2b0a
6.11	7.2	b99a1f0f18ee

Debian advisories