CVE-2023-54262 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Don't clone flow post action attributes second time
The code already clones post action attributes in mlx5e_clone_flow_attr_for_post_act(). Creating another copy in mlx5e_tc_post_act_add() is a erroneous leftover from original implementation. Instead, assign handle->attribute to post_attr provided by the caller. Note that cloning the attribute second time is not just wasteful but also causes issues like second copy not being properly updated in neigh update code which leads to following use-after-free:
Feb 21 09:02:00 c-237-177-40-045 kernel: BUG: KASAN: use-after-free in mlx5_cmd_set_fte+0x200d/0x24c0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_report+0xbb/0x1a0 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_save_stack+0x1e/0x40 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_set_track+0x21/0x30 Feb 21 09:02:00 c-237-177-40-045 kernel: __kasan_kmalloc+0x7a/0x90 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_save_stack+0x1e/0x40 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_set_track+0x21/0x30 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_save_free_info+0x2a/0x40 Feb 21 09:02:00 c-237-177-40-045 kernel: ____kasan_slab_free+0x11a/0x1b0 Feb 21 09:02:00 c-237-177-40-045 kernel: page dumped because: kasan: bad access detected Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_core 0000:08:00.0: mlx5_cmd_out_err:803:(pid 8833): SET_FLOW_TABLE_ENTRY(0x936) op_mod(0x0) failed, status bad resource state(0x9), syndrome (0xf2ff71), err(-22) Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_core 0000:08:00.0 enp8s0f0: Failed to add post action rule Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_core 0000:08:00.0: mlx5e_tc_encap_flows_add:190:(pid 8833): Failed to update flow post acts, -22 Feb 21 09:02:00 c-237-177-40-045 kernel: Call Trace: Feb 21 09:02:00 c-237-177-40-045 kernel: <TASK> Feb 21 09:02:00 c-237-177-40-045 kernel: dump_stack_lvl+0x57/0x7d Feb 21 09:02:00 c-237-177-40-045 kernel: print_report+0x170/0x471 Feb 21 09:02:00 c-237-177-40-045 kernel: ? mlx5_cmd_set_fte+0x200d/0x24c0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_report+0xbb/0x1a0 Feb 21 09:02:00 c-237-177-40-045 kernel: ? mlx5_cmd_set_fte+0x200d/0x24c0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_cmd_set_fte+0x200d/0x24c0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: ? __module_address.part.0+0x62/0x200 Feb 21 09:02:00 c-237-177-40-045 kernel: ? mlx5_cmd_stub_create_flow_table+0xd0/0xd0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: ? __raw_spin_lock_init+0x3b/0x110 Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_cmd_create_fte+0x80/0xb0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: add_rule_fg+0xe80/0x19c0 [mlx5_core]
-- Feb 21 09:02:00 c-237-177-40-045 kernel: Allocated by task 13476: Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_save_stack+0x1e/0x40 Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_set_track+0x21/0x30 Feb 21 09:02:00 c-237-177-40-045 kernel: __kasan_kmalloc+0x7a/0x90 Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5_packet_reformat_alloc+0x7b/0x230 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_tc_tun_create_header_ipv4+0x977/0xf10 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_attach_encap+0x15b4/0x1e10 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: post_process_attr+0x305/0xa30 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_tc_add_fdb_flow+0x4c0/0xcf0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: __mlx5e_add_fdb_flow+0x7cf/0xe90 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_configure_flower+0xcaa/0x4b90 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_rep_setup_tc_cls_flower+0x99/0x1b0 [mlx5_core]
Feb 21 09:02:00 c-237-177-40-045 kernel: mlx5e_rep_setup_tc_cb+0x133/0x1e0 [mlx5_core]
-- Feb 21 09:02:00 c-237-177-40-045 kernel: Freed by task 8833: Feb 21 09:02:00 c-237-177-40-045 kernel: kasan_save_s ---truncated---
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Analysis
by VulDB Data Team • 04/27/2026
The vulnerability CVE-2023-54262 resides within the Linux kernel's mlx5e network driver, specifically in the handling of flow post action attributes. This issue manifests as a double cloning of flow attributes during the processing of network traffic rules, which results in a use-after-free condition. The root cause lies in the mlx5e_tc_post_act_add() function where it redundantly clones flow attributes that have already been cloned in the mlx5e_clone_flow_attr_for_post_act() function. This erroneous duplication creates a memory management inconsistency that can lead to kernel crashes and potential security exploitation. The vulnerability directly impacts the mlx5_core module which manages Mellanox ConnectX network adapters and their associated traffic control mechanisms.
The technical flaw stems from improper memory management practices within the network flow table implementation. When the kernel processes traffic control rules for network devices, it must manage flow attributes that define how packets are handled. The original implementation included a redundant cloning operation that creates two separate copies of the same attribute structure. The first copy is created by mlx5e_clone_flow_attr_for_post_act() while the second copy is generated by mlx5e_tc_post_act_add(), leading to a situation where one copy gets freed while the other continues to be referenced. This memory inconsistency triggers kernel address sanitizer (KASAN) warnings and ultimately results in a use-after-free error when the freed memory is accessed during mlx5_cmd_set_fte() operations. The error manifests as a kernel panic with the specific error message indicating a bad resource state and syndrome value of 0xf2ff71, which corresponds to the mlx5 hardware driver's failure to process flow table entries.
The operational impact of this vulnerability extends beyond simple system instability to potential security implications within network infrastructure. Systems utilizing Mellanox network adapters and the mlx5e driver are at risk of experiencing kernel crashes, leading to service interruptions and potential denial of service conditions. The use-after-free condition can be exploited by malicious actors to potentially escalate privileges or cause system-wide instability. This vulnerability affects network environments where traffic control rules are actively managed, particularly in virtualized environments or systems implementing complex network policies. The issue is particularly concerning in high-availability networks where uninterrupted operation is critical, as the kernel crash can result in complete network service disruption.
Mitigation strategies for CVE-2023-54262 require applying the official kernel patch that removes the redundant cloning operation in the mlx5e driver. The fix involves modifying the mlx5e_tc_post_act_add() function to directly assign the already-cloned attribute handle->attribute to the post_attr parameter provided by the caller, eliminating the second unnecessary copy. System administrators should prioritize updating to kernel versions that include this fix, typically found in kernel releases 6.5 and later. Additionally, monitoring systems should be configured to detect KASAN warnings and kernel panic events related to mlx5_core module failures. Network administrators should also implement redundant monitoring for traffic control rule application failures and maintain rollback procedures for network infrastructure components that depend on the mlx5 driver. The fix aligns with common security practices outlined in the CWE-415 and CWE-416 categories, which address improper deallocation and double-free vulnerabilities, and follows ATT&CK tactics related to privilege escalation and denial of service through kernel exploitation.