Subject: CVE-2022-48699: sched/debug: fix dentry leak in update_sched_domain_debugfs

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

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

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

sched/debug: fix dentry leak in update_sched_domain_debugfs

Kuyo reports that the pattern of using debugfs_remove(debugfs_lookup())
leaks a dentry and with a hotplug stress test, the machine eventually
runs out of memory.

Fix this up by using the newly created debugfs_lookup_and_remove() call
instead which properly handles the dentry reference counting logic.

The Linux kernel CVE team has assigned CVE-2022-48699 to this issue.

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

	Fixed in 5.15.68 with commit 26e9a1ded892
	Fixed in 5.19.9 with commit 0c32a93963e0
	Fixed in 6.0 with commit c2e406596571

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-2022-48699
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/sched/debug.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/26e9a1ded8923510e5529fbb28390b22228700c2
	https://git.kernel.org/stable/c/0c32a93963e03c03e561d5a066eedad211880ba3
	https://git.kernel.org/stable/c/c2e406596571659451f4b95e37ddfd5a8ef1d0dc