CVE-2023-54148 net/mlx5e: Move representor neigh cleanup to profile cleanup_tx
A use-after-free in the mlx5e driver allows local attackers with high privileges to cause a system crash or potentially execute code during network interface unloading.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54148?
CVE-2023-54148 is an use after free vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Move representor neigh cleanup to profile cleanup_tx
For IP tunnel encapsulation in ECMP (Equal-Cost Multipath) mode, as the flow is duplicated to the peer eswitch, the related neighbour information on the peer uplink representor is created as well.
In the cited commit, eswitch devcom unpair is moved to uplink unload API, specifically the profile->cleanup_tx. If there is a encap rule offloaded in ECMP mode, when one eswitch does unpair (because of unloading the driver, for instance), and the peer rule from the peer eswitch is going to be deleted, the use-after-free error is triggered while accessing neigh info, as it is already cleaned up in uplink's profile->disable, which is before its profile->cleanup_tx.
To fix this issue, move the neigh cleanup to profile's cleanup_tx callback, and after mlx5e_cleanup_uplink_rep_tx is called. The neigh init is moved to init_tx for symmeter.
[ 2453.376299] BUG: KASAN: slab-use-after-free in mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.379125] Read of size 4 at addr ffff888127af9008 by task modprobe/2496
[ 2453.381542] CPU: 7 PID: 2496 Comm: modprobe Tainted: G B 6.4.0-rc7+ #15 [ 2453.383386] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 2453.384335] Call Trace: [ 2453.384625] <TASK> [ 2453.384891] dump_stack_lvl+0x33/0x50 [ 2453.385285] print_report+0xc2/0x610 [ 2453.385667] ? __virt_addr_valid+0xb1/0x130 [ 2453.386091] ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.386757] kasan_report+0xae/0xe0 [ 2453.387123] ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.387798] mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.388465] mlx5e_rep_encap_entry_detach+0xa6/0xe0 [mlx5_core] [ 2453.389111] mlx5e_encap_dealloc+0xa7/0x100 [mlx5_core] [ 2453.389706] mlx5e_tc_tun_encap_dests_unset+0x61/0xb0 [mlx5_core] [ 2453.390361] mlx5_free_flow_attr_actions+0x11e/0x340 [mlx5_core] [ 2453.391015] ? complete_all+0x43/0xd0 [ 2453.391398] ? free_flow_post_acts+0x38/0x120 [mlx5_core] [ 2453.392004] mlx5e_tc_del_fdb_flow+0x4ae/0x690 [mlx5_core] [ 2453.392618] mlx5e_tc_del_fdb_peers_flow+0x308/0x370 [mlx5_core] [ 2453.393276] mlx5e_tc_clean_fdb_peer_flows+0xf5/0x140 [mlx5_core] [ 2453.393925] mlx5_esw_offloads_unpair+0x86/0x540 [mlx5_core] [ 2453.394546] ? mlx5_esw_offloads_set_ns_peer.isra.0+0x180/0x180 [mlx5_core] [ 2453.395268] ? down_write+0xaa/0x100 [ 2453.395652] mlx5_esw_offloads_devcom_event+0x203/0x530 [mlx5_core] [ 2453.396317] mlx5_devcom_send_event+0xbb/0x190 [mlx5_core] [ 2453.396917] mlx5_esw_offloads_devcom_cleanup+0xb0/0xd0 [mlx5_core] [ 2453.397582] mlx5e_tc_esw_cleanup+0x42/0x120 [mlx5_core] [ 2453.398182] mlx5e_rep_tc_cleanup+0x15/0x30 [mlx5_core] [ 2453.398768] mlx5e_cleanup_rep_tx+0x6c/0x80 [mlx5_core] [ 2453.399367] mlx5e_detach_netdev+0xee/0x120 [mlx5_core] [ 2453.399957] mlx5e_netdev_change_profile+0x84/0x170 [mlx5_core] [ 2453.400598] mlx5e_vport_rep_unload+0xe0/0xf0 [mlx5_core] [ 2453.403781] mlx5_eswitch_unregister_vport_reps+0x15e/0x190 [mlx5_core] [ 2453.404479] ? mlx5_eswitch_register_vport_reps+0x200/0x200 [mlx5_core] [ 2453.405170] ? up_write+0x39/0x60 [ 2453.405529] ? kernfs_remove_by_name_ns+0xb7/0xe0 [ 2453.405985] auxiliary_bus_remove+0x2e/0x40 [ 2453.406405] device_release_driver_internal+0x243/0x2d0 [ 2453.406900] ? kobject_put+0x42/0x2d0 [ 2453.407284] bus_remove_device+0x128/0x1d0 [ 2453.407687] device_del+0x240/0x550 [ 2453.408053] ? waiting_for_supplier_show+0xe0/0xe0 [ 2453.408511] ? kobject_put+0xfa/0x2d0 [ 2453.408889] ? __kmem_cache_free+0x14d/0x280 [ 2453.409310] mlx5_rescan_drivers_locked.part.0+0xcd/0x2b0 [mlx5_core] [ 2453.409973] mlx5_unregister_device+0x40/0x50 [mlx5_core] [ 2453.410561] mlx5_uninit_one+0x3d/0x110 [mlx5_core] [ 2453.411111] remove_one+0x89/0x130 [mlx5_core] [ 24 ---truncated---
Which versions are affected by CVE-2023-54148?
How do I fix CVE-2023-54148?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-54148 being exploited?
There is no known exploitation of CVE-2023-54148 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54148, DEBIAN-CVE-2023-54148, GHSA-hr7g-x38j-56v5, UBUNTU-CVE-2023-54148.