CVE-2026-72462: apparmor: fix race in unix socket mediation when peer_path is used

CVE-2026-72462: apparmor: fix race in unix socket mediation when peer_path is used

[Greg Kroah-Hartman]

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

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

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

apparmor: fix race in unix socket mediation when peer_path is used

The holding a reference to the peer_sk is not enough to ensure access
to the peer sk path. Accessing the path outside of the state lock
allows for a race with unix_release_sock(). Fix this by taking the
state lock and getting a reference to the path under lock.

Ideally for connected sockets we would cache this information so we
don't have to take the lock here. But for now just fix the race.

The Linux kernel CVE team has assigned CVE-2026-72462 to this issue.


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

	Issue introduced in 6.17 with commit bc6e5f6933b8e7b74858ac830d5b9b4ca10a099a and fixed in 6.18.40 with commit d8ea44f6090c087fe255d9512fb808574b4d88e8
	Issue introduced in 6.17 with commit bc6e5f6933b8e7b74858ac830d5b9b4ca10a099a and fixed in 7.1.5 with commit d680472db98823d90fc91362910901e468269318
	Issue introduced in 6.17 with commit bc6e5f6933b8e7b74858ac830d5b9b4ca10a099a and fixed in 7.2-rc1 with commit b1aea2c1960771a276d7e68c7424168eccd0c3da

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-2026-72462
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:
	security/apparmor/af_unix.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/d8ea44f6090c087fe255d9512fb808574b4d88e8
	https://git.kernel.org/stable/c/d680472db98823d90fc91362910901e468269318
	https://git.kernel.org/stable/c/b1aea2c1960771a276d7e68c7424168eccd0c3da