linux-cve-announce - CVE-2026-23001: macvlan: fix possible UAF in macvlan_forward

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2026012534-CVE-2026-23001-7ab0@gregkh>
Date: Sun, 25 Jan 2026 15:36:37 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2026-23001: macvlan: fix possible UAF in macvlan_forward_source()

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

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

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

macvlan: fix possible UAF in macvlan_forward_source()

Add RCU protection on (struct macvlan_source_entry)->vlan.

Whenever macvlan_hash_del_source() is called, we must clear
entry->vlan pointer before RCU grace period starts.

This allows macvlan_forward_source() to skip over
entries queued for freeing.

Note that macvlan_dev are already RCU protected, as they
are embedded in a standard netdev (netdev_priv(ndev)).

https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@...gle.com/T/#u

The Linux kernel CVE team has assigned CVE-2026-23001 to this issue.


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

	Issue introduced in 3.18 with commit 79cf79abce71eb7dbc40e2f3121048ca5405cb47 and fixed in 6.12.67 with commit 8518712a2ca952d6da2238c6f0a16b4ae5ea3f13
	Issue introduced in 3.18 with commit 79cf79abce71eb7dbc40e2f3121048ca5405cb47 and fixed in 6.18.7 with commit 6dbead9c7677186f22b7981dd085a0feec1f038e
	Issue introduced in 3.18 with commit 79cf79abce71eb7dbc40e2f3121048ca5405cb47 and fixed in 6.19-rc6 with commit 7470a7a63dc162f07c26dbf960e41ee1e248d80e

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-2026-23001
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:
	drivers/net/macvlan.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/8518712a2ca952d6da2238c6f0a16b4ae5ea3f13
	https://git.kernel.org/stable/c/6dbead9c7677186f22b7981dd085a0feec1f038e
	https://git.kernel.org/stable/c/7470a7a63dc162f07c26dbf960e41ee1e248d80e