CVE-2026-64356 xfs: fix memory leak in xfs_dqinode_metadir_create()

Medium 5.5 Published Updated

A memory leak in the Linux kernel XFS filesystem can cause mount failures and resource exhaustion, requiring a kernel patch.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-64356?

CVE-2026-64356 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-401

Which versions are affected by CVE-2026-64356?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-64356?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-64356 being exploited?

There is no known exploitation of CVE-2026-64356 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-64356, DEBIAN-CVE-2026-64356, GHSA-p28w-6j9h-mmp2, ROOT-OS-UBUNTU-2204-CVE-2026-64356, UBUNTU-CVE-2026-64356.

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