Subject: CVE-2024-42307: cifs: fix potential null pointer use in destroy_workqueue in init_cifs error path

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

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

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

cifs: fix potential null pointer use in destroy_workqueue in init_cifs error path

Dan Carpenter reported a Smack static checker warning:
   fs/smb/client/cifsfs.c:1981 init_cifs()
   error: we previously assumed 'serverclose_wq' could be null (see line 1895)

The patch which introduced the serverclose workqueue used the wrong
oredering in error paths in init_cifs() for freeing it on errors.

The Linux kernel CVE team has assigned CVE-2024-42307 to this issue.

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

	Issue introduced in 6.1.85 with commit 8c99dfb49bdc and fixed in 6.1.103 with commit 6018971710fd
	Issue introduced in 6.6.26 with commit 6f17163b9339 and fixed in 6.6.44 with commit 160235efb4f9
	Issue introduced in 6.9 with commit 173217bd7336 and fixed in 6.10.3 with commit 3739d711246d
	Issue introduced in 6.9 with commit 173217bd7336 and fixed in 6.11 with commit 193cc89ea0ca
	Issue introduced in 6.8.5 with commit 40a5d14c9d3b

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-2024-42307
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/smb/client/cifsfs.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/6018971710fdc7739f8655c1540832b4bb903671
	https://git.kernel.org/stable/c/160235efb4f9b55212dedff5de0094c606c4b303
	https://git.kernel.org/stable/c/3739d711246d8fbc95ff73dbdace9741cdce4777
	https://git.kernel.org/stable/c/193cc89ea0ca1da311877d2b4bb5e9f03bcc82a2