Bug 2507202 (CVE-2026-64356)

Summary:	CVE-2026-64356 kernel: xfs: fix memory leak in xfs_dqinode_metadir_create()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's XFS filesystem. This vulnerability occurs during the creation of XFS metadata directories, where a failure in the creation process or a subsequent commit can lead to a memory leak. This leak results in allocated update and transaction state not being properly released, and an inode reference being left behind. Over time, this can lead to resource exhaustion and potentially cause the system to become unresponsive, resulting in a Denial of Service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:10:23 UTC

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

xfs: fix memory leak in xfs_dqinode_metadir_create()

If xfs_metadir_create() fails in xfs_dqinode_metadir_create(), the current
code returns directly, leaking the allocated update and transaction state.
If the subsequent commit fails, the caller-owned inode reference is left
behind.

Fix this memory leak by routing the create failure path through
xfs_metadir_cancel().  For both create and commit failures, finish and
release any inode returned to the caller, mirroring the unwind pattern in
xfs_metadir_mkdir().

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.

An x86_64 allyesconfig build showed no new warnings. Runtime validation
used kprobe fault injection during `mount -o uquota` on a metadir XFS
image. Injecting xfs_metadir_create() reproduced the old active-update path
that left mount stuck later in mount setup; after this change, the same
injection reported cancel_hits=1 and irele_hits=1. Injecting
xfs_metadir_commit() exercised the old inode-reference leak path; after
this change, it reported irele_hits=1.

Comment 1 TEJ RATHI 2026-07-29 09:57:15 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072519-CVE-2026-64356-d9e2@gregkh/T