CVE-2024-43846

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>