Subject: CVE-2023-52442: ksmbd: validate session id and tree id in compound request

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

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

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

ksmbd: validate session id and tree id in compound request

`smb2_get_msg()` in smb2_get_ksmbd_tcon() and smb2_check_user_session()
will always return the first request smb2 header in a compound request.
if `SMB2_TREE_CONNECT_HE` is the first command in compound request, will
return 0, i.e. The tree id check is skipped.
This patch use ksmbd_req_buf_next() to get current command in compound.

The Linux kernel CVE team has assigned CVE-2023-52442 to this issue.

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

	Fixed in 5.15.145 with commit 017d85c94f02
	Fixed in 6.1.53 with commit becb5191d1d5
	Fixed in 6.4.16 with commit 4c2b350b2e26
	Fixed in 6.5 with commit 3df0411e132e

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-2023-52442
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/server/smb2pdu.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/017d85c94f02090a87f4a473dbe0d6ee0da72693
	https://git.kernel.org/stable/c/becb5191d1d5fdfca0198a2e37457bbbf4fe266f
	https://git.kernel.org/stable/c/4c2b350b2e269e3fd17bbfa42de1b42775b777ac
	https://git.kernel.org/stable/c/3df0411e132ee74a87aa13142dfd2b190275332e