CVE-2026-98444: xfs: drop dquot flush lock when we can't find a buffer to flush

CVE-2026-98444: xfs: drop dquot flush lock when we can't find a buffer to flush

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

xfs: drop dquot flush lock when we can't find a buffer to flush

LOLLM noticed that xfs_qm_flush_one fails to drop the dquot flush lock
if it can't grab the buffer associated with the dquot.  Since there's no
buffer, nobody else is going to drop the dqflock, so we need to do it
ourselves.

The Linux kernel CVE team has assigned CVE-2026-98444 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.13 with commit ca378189fdfa890a4f0622f85ee41b710bbac271 and fixed in 7.2.9 with commit 41bc624377f08125eae164c62ce043791ade93b7
	Issue introduced in 6.13 with commit ca378189fdfa890a4f0622f85ee41b710bbac271 and fixed in 7.3-rc5 with commit ffb48dccce1960a9ea24463a2f3c21d124d6b672
	Issue introduced in 6.12.14 with commit d331fc154564548b605cde8427442b54c87d7fd3

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-98444
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/xfs/xfs_qm.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/41bc624377f08125eae164c62ce043791ade93b7
	https://git.kernel.org/stable/c/ffb48dccce1960a9ea24463a2f3c21d124d6b672