Subject: CVE-2022-48638: cgroup: cgroup_get_from_id() must check the looked-up kn is a directory

From: Greg Kroah-Hartman <[email-masked]>

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

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

cgroup: cgroup_get_from_id() must check the looked-up kn is a directory

cgroup has to be one kernfs dir, otherwise kernel panic is caused,
especially cgroup id is provide from userspace.

The Linux kernel CVE team has assigned CVE-2022-48638 to this issue.

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

	Issue introduced in 5.14 with commit 6b658c4863c1 and fixed in 5.15.72 with commit 8484a356cee8
	Issue introduced in 5.14 with commit 6b658c4863c1 and fixed in 5.19.12 with commit 1e9571887f97
	Issue introduced in 5.14 with commit 6b658c4863c1 and fixed in 6.0 with commit df02452f3df0

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-2022-48638
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:
	kernel/cgroup/cgroup.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/8484a356cee8ce3d6a8e6266ff99be326e9273ad
	https://git.kernel.org/stable/c/1e9571887f97b17cf3ffe9aa4da89090ea60988b
	https://git.kernel.org/stable/c/df02452f3df069a59bc9e69c84435bf115cb6e37