CVE-2026-89609: ecryptfs: hold msg ctx list lock when cleaning daemon queue

CVE-2026-89609: ecryptfs: hold msg ctx list lock when cleaning daemon queue

[Greg Kroah-Hartman]

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

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

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

ecryptfs: hold msg ctx list lock when cleaning daemon queue

ecryptfs_exorcise_daemon() drops queued messages from a dying daemon
without holding ecryptfs_msg_ctx_lists_mux, but
ecryptfs_msg_ctx_alloc_to_free() requires that lock.

Take the list lock while moving the queued contexts back to the free
list to avoid racing with other global msg ctx list users.

The Linux kernel CVE team has assigned CVE-2026-89609 to this issue.


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

	Issue introduced in 2.6.26 with commit f66e883eb6186bc43a79581b67aff7d1a69d0ff1 and fixed in 6.12.109 with commit 7e48afafe7abc275f7b6916613bb18b821e7d94a
	Issue introduced in 2.6.26 with commit f66e883eb6186bc43a79581b67aff7d1a69d0ff1 and fixed in 6.18.50 with commit 0d9636ecba34bd553ecf19049f7705505aea62fd
	Issue introduced in 2.6.26 with commit f66e883eb6186bc43a79581b67aff7d1a69d0ff1 and fixed in 7.2.4 with commit 4c02acbe0a2692ca9991c51e62bbe6d6b59dac31
	Issue introduced in 2.6.26 with commit f66e883eb6186bc43a79581b67aff7d1a69d0ff1 and fixed in 7.3-rc1 with commit 779972513c2fa8c7938e54976f686091dafff22f

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-2026-89609
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:
	fs/ecryptfs/messaging.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/7e48afafe7abc275f7b6916613bb18b821e7d94a
	https://git.kernel.org/stable/c/0d9636ecba34bd553ecf19049f7705505aea62fd
	https://git.kernel.org/stable/c/4c02acbe0a2692ca9991c51e62bbe6d6b59dac31
	https://git.kernel.org/stable/c/779972513c2fa8c7938e54976f686091dafff22f