Subject: CVE-2024-35855: mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update

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

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

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

mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update

The rule activity update delayed work periodically traverses the list of
configured rules and queries their activity from the device.

As part of this task it accesses the entry pointed by 'ventry->entry',
but this entry can be changed concurrently by the rehash delayed work,
leading to a use-after-free [1].

Fix by closing the race and perform the activity query under the
'vregion->lock' mutex.

[1]
BUG: KASAN: slab-use-after-free in mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
Read of size 8 at addr ffff8881054ed808 by task kworker/0:18/181

CPU: 0 PID: 181 Comm: kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xc6/0x120
 print_report+0xce/0x670
 kasan_report+0xd7/0x110
 mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
 mlxsw_sp_acl_rule_activity_update_work+0x219/0x400
 process_one_work+0x8eb/0x19b0
 worker_thread+0x6c9/0xf70
 kthread+0x2c9/0x3b0
 ret_from_fork+0x4d/0x80
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 1039:
 kasan_save_stack+0x33/0x60
 kasan_save_track+0x14/0x30
 __kasan_kmalloc+0x8f/0xa0
 __kmalloc+0x19c/0x360
 mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0
 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50
 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
 process_one_work+0x8eb/0x19b0
 worker_thread+0x6c9/0xf70
 kthread+0x2c9/0x3b0
 ret_from_fork+0x4d/0x80
 ret_from_fork_asm+0x1a/0x30

Freed by task 1039:
 kasan_save_stack+0x33/0x60
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 poison_slab_object+0x102/0x170
 __kasan_slab_free+0x14/0x30
 kfree+0xc1/0x290
 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50
 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
 process_one_work+0x8eb/0x19b0
 worker_thread+0x6c9/0xf70
 kthread+0x2c9/0x3b0
 ret_from_fork+0x4d/0x80
 ret_from_fork_asm+0x1a/0x30

The Linux kernel CVE team has assigned CVE-2024-35855 to this issue.

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

	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 5.4.275 with commit 1b73f6e4ea77
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 5.10.216 with commit e24d24874247
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 5.15.158 with commit c17976b42d54
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 6.1.90 with commit b996e8699da8
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 6.6.30 with commit feabdac2057e
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 6.8.9 with commit b183b915beef
	Issue introduced in 5.1 with commit 2bffc5322fd8 and fixed in 6.9 with commit 79b5b4b18bc8

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-2024-35855
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/1b73f6e4ea770410a937a8db98f77e52594d23a0
	https://git.kernel.org/stable/c/e24d2487424779c02760ff50cd9021b8676e19ef
	https://git.kernel.org/stable/c/c17976b42d546ee118ca300db559630ee96fb758
	https://git.kernel.org/stable/c/b996e8699da810e4c915841d6aaef761007f933a
	https://git.kernel.org/stable/c/feabdac2057e863d0e140a2adf3d232eb4882db4
	https://git.kernel.org/stable/c/b183b915beef818a25e3154d719ca015a1ae0770
	https://git.kernel.org/stable/c/79b5b4b18bc85b19d3a518483f9abbbe6d7b3ba4