CVE-2026-68153: libceph: remove debugfs files before client teardown

CVE-2026-68153: libceph: remove debugfs files before client teardown

[Greg Kroah-Hartman]

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

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

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

libceph: remove debugfs files before client teardown

ceph_destroy_client() tears down the monitor client before removing
the per-client debugfs files. A concurrent read of the monmap debugfs
file can enter monmap_show() after ceph_monc_stop() has freed
monc->monmap, triggering a use-after-free.

Remove the debugfs files before stopping the OSD and monitor clients.
debugfs_remove() drains active handlers and prevents new accesses, so
the debugfs callbacks can no longer race the rest of client teardown.

The Linux kernel CVE team has assigned CVE-2026-68153 to this issue.


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

	Issue introduced in 2.6.34 with commit 76aa844d5b2fb8c839180d3f5874e333b297e5fd and fixed in 6.6.148 with commit fc1010e7e0204ece6cc0f9af4f473e9553535eab
	Issue introduced in 2.6.34 with commit 76aa844d5b2fb8c839180d3f5874e333b297e5fd and fixed in 6.12.101 with commit d3dc8889d39a676bf840132bd5c5c48cb0daba23
	Issue introduced in 2.6.34 with commit 76aa844d5b2fb8c839180d3f5874e333b297e5fd and fixed in 6.18.42 with commit 8f5a3abc54ba24dbceb14cc3a719908c4f688091
	Issue introduced in 2.6.34 with commit 76aa844d5b2fb8c839180d3f5874e333b297e5fd and fixed in 7.1.6 with commit b9fedda2f628e030384228de0dafc574b7fb0c2f
	Issue introduced in 2.6.34 with commit 76aa844d5b2fb8c839180d3f5874e333b297e5fd and fixed in 7.2-rc5 with commit e4c804726c4afce3ba648b982d564f6af2cfa328

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-2026-68153
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:
	net/ceph/ceph_common.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/fc1010e7e0204ece6cc0f9af4f473e9553535eab
	https://git.kernel.org/stable/c/d3dc8889d39a676bf840132bd5c5c48cb0daba23
	https://git.kernel.org/stable/c/8f5a3abc54ba24dbceb14cc3a719908c4f688091
	https://git.kernel.org/stable/c/b9fedda2f628e030384228de0dafc574b7fb0c2f
	https://git.kernel.org/stable/c/e4c804726c4afce3ba648b982d564f6af2cfa328