CVE-2023-54216 net/mlx5e: TC, Fix using eswitch mapping in nic mode
A use-after-free vulnerability in the Linux kernel mlx5 driver allows attackers to cause a denial of service or potentially execute code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54216?
CVE-2023-54216 is a high-severity use after free vulnerability in Linux, published on 30 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: TC, Fix using eswitch mapping in nic mode
Cited patch is using the eswitch object mapping pool while in nic mode where it isn't initialized. This results in the trace below [0].
Fix that by using either nic or eswitch object mapping pool depending if eswitch is enabled or not.
[0]: [ 826.446057] ================================================================== [ 826.446729] BUG: KASAN: slab-use-after-free in mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.447515] Read of size 8 at addr ffff888194485830 by task tc/6233
[ 826.448243] CPU: 16 PID: 6233 Comm: tc Tainted: G W 6.3.0-rc6+ #1 [ 826.448890] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 826.449785] Call Trace: [ 826.450052] <TASK> [ 826.450302] dump_stack_lvl+0x33/0x50 [ 826.450650] print_report+0xc2/0x610 [ 826.450998] ? __virt_addr_valid+0xb1/0x130 [ 826.451385] ? mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.451935] kasan_report+0xae/0xe0 [ 826.452276] ? mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.452829] mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.453368] ? __kmalloc_node+0x5a/0x120 [ 826.453733] esw_add_restore_rule+0x20f/0x270 [mlx5_core] [ 826.454288] ? mlx5_eswitch_add_send_to_vport_meta_rule+0x260/0x260 [mlx5_core] [ 826.455011] ? mutex_unlock+0x80/0xd0 [ 826.455361] ? __mutex_unlock_slowpath.constprop.0+0x210/0x210 [ 826.455862] ? mapping_add+0x2cb/0x440 [mlx5_core] [ 826.456425] mlx5e_tc_action_miss_mapping_get+0x139/0x180 [mlx5_core] [ 826.457058] ? mlx5e_tc_update_skb_nic+0xb0/0xb0 [mlx5_core] [ 826.457636] ? __kasan_kmalloc+0x77/0x90 [ 826.458000] ? __kmalloc+0x57/0x120 [ 826.458336] mlx5_tc_ct_flow_offload+0x325/0xe40 [mlx5_core] [ 826.458916] ? ct_kernel_enter.constprop.0+0x48/0xa0 [ 826.459360] ? mlx5_tc_ct_parse_action+0xf0/0xf0 [mlx5_core] [ 826.459933] ? mlx5e_mod_hdr_attach+0x491/0x520 [mlx5_core] [ 826.460507] ? mlx5e_mod_hdr_get+0x12/0x20 [mlx5_core] [ 826.461046] ? mlx5e_tc_attach_mod_hdr+0x154/0x170 [mlx5_core] [ 826.461635] mlx5e_configure_flower+0x969/0x2110 [mlx5_core] [ 826.462217] ? _raw_spin_lock_bh+0x85/0xe0 [ 826.462597] ? __mlx5e_add_fdb_flow+0x750/0x750 [mlx5_core] [ 826.463163] ? kasan_save_stack+0x2e/0x40 [ 826.463534] ? down_read+0x115/0x1b0 [ 826.463878] ? down_write_killable+0x110/0x110 [ 826.464288] ? tc_setup_action.part.0+0x9f/0x3b0 [ 826.464701] ? mlx5e_is_uplink_rep+0x4c/0x90 [mlx5_core] [ 826.465253] ? mlx5e_tc_reoffload_flows_work+0x130/0x130 [mlx5_core] [ 826.465878] tc_setup_cb_add+0x112/0x250 [ 826.466247] fl_hw_replace_filter+0x230/0x310 [cls_flower] [ 826.466724] ? fl_hw_destroy_filter+0x1a0/0x1a0 [cls_flower] [ 826.467212] fl_change+0x14e1/0x2030 [cls_flower] [ 826.467636] ? sock_def_readable+0x89/0x120 [ 826.468019] ? fl_tmplt_create+0x2d0/0x2d0 [cls_flower] [ 826.468509] ? kasan_unpoison+0x23/0x50 [ 826.468873] ? get_random_u16+0x180/0x180 [ 826.469244] ? __radix_tree_lookup+0x2b/0x130 [ 826.469640] ? fl_get+0x7b/0x140 [cls_flower] [ 826.470042] ? fl_mask_put+0x200/0x200 [cls_flower] [ 826.470478] ? __mutex_unlock_slowpath.constprop.0+0x210/0x210 [ 826.470973] ? fl_tmplt_create+0x2d0/0x2d0 [cls_flower] [ 826.471427] tc_new_tfilter+0x644/0x1050 [ 826.471795] ? tc_get_tfilter+0x860/0x860 [ 826.472170] ? __thaw_task+0x130/0x130 [ 826.472525] ? arch_stack_walk+0x98/0xf0 [ 826.472892] ? cap_capable+0x9f/0xd0 [ 826.473235] ? security_capable+0x47/0x60 [ 826.473608] rtnetlink_rcv_msg+0x1d5/0x550 [ 826.473985] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 826.474383] ? __stack_depot_save+0x35/0x4c0 [ 826.474779] ? kasan_save_stack+0x2e/0x40 [ 826.475149] ? kasan_save_stack+0x1e/0x40 [ 826.475518] ? __kasan_record_aux_stack+0x9f/0xb0 [ 826.475939] ? task_work_add+0x77/0x1c0 [ 826.476305] netlink_rcv_skb+0xe0/0x210 ---truncated---
Which versions are affected by CVE-2023-54216?
How do I fix CVE-2023-54216?
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-2023-54216 being exploited?
There is no known exploitation of CVE-2023-54216 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54216, GHSA-7cww-g38x-r47j, UBUNTU-CVE-2023-54216.