CVE-2026-80912: selinux: reject an unclaimed class value in security_get_classes()

CVE-2026-80912: selinux: reject an unclaimed class value in security_get_classes()

[Greg Kroah-Hartman]

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

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

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

selinux: reject an unclaimed class value in security_get_classes()

security_get_classes() sizes an array by p_classes.nprim and fills it at
value - 1, so a class value the policy never defines leaves a NULL.
sel_make_classes() passes every entry to sel_make_dir(), reaching the same
d_alloc_name() dereference as the permission array. The class symbol table
is allowed to be sparse (policydb_class_isvalid() exists to absorb that),
but this getter builds its own array straight from the hash table and has
no such predicate.

Fail the lookup when a value went unclaimed instead of handing out the
NULL. Conforming policies define every class they declare and are
unaffected.

The Linux kernel CVE team has assigned CVE-2026-80912 to this issue.


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

	Issue introduced in 2.6.23 with commit 55fcf09b3fe4325c9395ebbb0322a547a157ebc7 and fixed in 6.6.153 with commit e0285bb152211c00900136b66d4b420c14a59094
	Issue introduced in 2.6.23 with commit 55fcf09b3fe4325c9395ebbb0322a547a157ebc7 and fixed in 6.12.105 with commit 099869e9343a5f8c22b58497f074b34f63cbf856
	Issue introduced in 2.6.23 with commit 55fcf09b3fe4325c9395ebbb0322a547a157ebc7 and fixed in 6.18.46 with commit 841aea4d5a25e16273d04cd07a74142b4687e03b
	Issue introduced in 2.6.23 with commit 55fcf09b3fe4325c9395ebbb0322a547a157ebc7 and fixed in 7.1.10 with commit d8a10899ea3c84b80de72ca8ee9039e9a5156c9a
	Issue introduced in 2.6.23 with commit 55fcf09b3fe4325c9395ebbb0322a547a157ebc7 and fixed in 7.2 with commit 22b05fec62c0fe9864cfceb52f7d0f3a34d9b1dd

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-2026-80912
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/selinux/ss/services.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/e0285bb152211c00900136b66d4b420c14a59094
	https://git.kernel.org/stable/c/099869e9343a5f8c22b58497f074b34f63cbf856
	https://git.kernel.org/stable/c/841aea4d5a25e16273d04cd07a74142b4687e03b
	https://git.kernel.org/stable/c/d8a10899ea3c84b80de72ca8ee9039e9a5156c9a
	https://git.kernel.org/stable/c/22b05fec62c0fe9864cfceb52f7d0f3a34d9b1dd