Subject: CVE-2024-43846: lib: objagg: Fix general protection fault

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

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

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

lib: objagg: Fix general protection fault

The library supports aggregation of objects into other objects only if
the parent object does not have a parent itself. That is, nesting is not
supported.

Aggregation happens in two cases: Without and with hints, where hints
are a pre-computed recommendation on how to aggregate the provided
objects.

Nesting is not possible in the first case due to a check that prevents
it, but in the second case there is no check because the assumption is
that nesting cannot happen when creating objects based on hints. The
violation of this assumption leads to various warnings and eventually to
a general protection fault [1].

Before fixing the root cause, error out when nesting happens and warn.

[1]
general protection fault, probably for non-canonical address 0xdead000000000d90: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 1083 Comm: kworker/1:9 Tainted: G        W          6.9.0-rc6-custom-gd9b4f1cca7fb #7
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_erp_bf_insert+0x25/0x80
[...]
Call Trace:
 <TASK>
 mlxsw_sp_acl_atcam_entry_add+0x256/0x3c0
 mlxsw_sp_acl_tcam_entry_create+0x5e/0xa0
 mlxsw_sp_acl_tcam_vchunk_migrate_one+0x16b/0x270
 mlxsw_sp_acl_tcam_vregion_rehash_work+0xbe/0x510
 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-2024-43846 to this issue.

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

	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 5.4.282 with commit 816126336215
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 5.10.224 with commit 22ae17a267f4
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 5.15.165 with commit 565213e00555
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 6.1.103 with commit 5adc61d29bbb
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 6.6.44 with commit 1936fa05a180
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 6.10.3 with commit 499f742fed42
	Issue introduced in 5.1 with commit 9069a3817d82 and fixed in 6.11 with commit b4a3a89fffcd

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-2024-43846
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:
	lib/objagg.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/8161263362154cbebfbf4808097b956a6a8cb98a
	https://git.kernel.org/stable/c/22ae17a267f4812861f0c644186c3421ff97dbfc
	https://git.kernel.org/stable/c/565213e005557eb6cc4e42189d26eb300e02f170
	https://git.kernel.org/stable/c/5adc61d29bbb461d7f7c2b48dceaa90ecd182eb7
	https://git.kernel.org/stable/c/1936fa05a180834c3b52e0439a6bddc07814d3eb
	https://git.kernel.org/stable/c/499f742fed42e74f1321f4b12ca196a66a2b49fc
	https://git.kernel.org/stable/c/b4a3a89fffcdf09702b1f161b914e52abca1894d