Subject: CVE-2024-36006: mlxsw: spectrum_acl_tcam: Fix incorrect list API usage

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

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

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

mlxsw: spectrum_acl_tcam: Fix incorrect list API usage

Both the function that migrates all the chunks within a region and the
function that migrates all the entries within a chunk call
list_first_entry() on the respective lists without checking that the
lists are not empty. This is incorrect usage of the API, which leads to
the following warning [1].

Fix by returning if the lists are empty as there is nothing to migrate
in this case.

[1]
WARNING: CPU: 0 PID: 6437 at drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:1266 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x1f1/0>
Modules linked in:
CPU: 0 PID: 6437 Comm: kworker/0:37 Not tainted 6.9.0-rc3-custom-00883-g94a65f079ef6 #39
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work
RIP: 0010:mlxsw_sp_acl_tcam_vchunk_migrate_all+0x1f1/0x2c0
[...]
Call Trace:
 <TASK>
 mlxsw_sp_acl_tcam_vregion_rehash_work+0x6c/0x4a0
 process_one_work+0x151/0x370
 worker_thread+0x2cb/0x3e0
 kthread+0xd0/0x100
 ret_from_fork+0x34/0x50
 ret_from_fork_asm+0x1a/0x30
 </TASK>

The Linux kernel CVE team has assigned CVE-2024-36006 to this issue.

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

	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 5.4.275 with commit 0b2c13b670b1
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 5.10.216 with commit 09846c2309b1
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 5.15.158 with commit 64435b64e43d
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 6.1.90 with commit 4526a56e02da
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 6.6.30 with commit ab4ecfb62733
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 6.8.9 with commit af8b593c3dd9
	Issue introduced in 5.1 with commit 6f9579d4e302 and fixed in 6.9 with commit b377add0f011

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-2024-36006
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:
	drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.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/0b2c13b670b168e324e1cf109e67056a20fd610a
	https://git.kernel.org/stable/c/09846c2309b150b8ce4e0ce96f058197598fc530
	https://git.kernel.org/stable/c/64435b64e43d8ee60faa46c0cd04e323e8b2a7b0
	https://git.kernel.org/stable/c/4526a56e02da3725db979358964df9cd9c567154
	https://git.kernel.org/stable/c/ab4ecfb627338e440ae11def004c524a00d93e40
	https://git.kernel.org/stable/c/af8b593c3dd9df82cb199be65863af004b09fd97
	https://git.kernel.org/stable/c/b377add0f0117409c418ddd6504bd682ebe0bf79