CVE-2023-54262
Unknown Unknown - Not Provided
Use-After-Free in Linux mlx5e Driver Due to Double Attribute Cloning

Publication date: 2025-12-30

Last updated on: 2025-12-30

Assigner: kernel.org

Description
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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Meta Information
Published
2025-12-30
Last Modified
2025-12-30
Generated
2026-05-07
AI Q&A
2025-12-30
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
mlx5 mlx5_core *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel's mlx5e driver involves improper handling of flow post action attributes. The code mistakenly clones these attributes twice, which is unnecessary and leads to a use-after-free error. Specifically, the second cloned copy is not properly updated, causing memory access issues that can result in kernel bugs and crashes.


How can this vulnerability impact me? :

The vulnerability can cause kernel crashes or instability due to use-after-free errors in the mlx5e driver. This can lead to system reliability issues, potential denial of service, and unexpected behavior in network operations relying on this driver.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring kernel logs for specific error messages related to the mlx5_core module, such as use-after-free bugs reported by KASAN (Kernel Address Sanitizer). Look for log entries mentioning 'BUG: KASAN: use-after-free in mlx5_cmd_set_fte', 'mlx5_core: Failed to add post action rule', or 'Failed to update flow post acts'. Commands to check these logs include: 'dmesg | grep mlx5_core' or 'journalctl -k | grep mlx5_core'.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation involves updating the Linux kernel to a version where this vulnerability is fixed, as the issue is resolved by correcting the cloning of flow post action attributes in the mlx5e driver. Until an update is applied, monitoring for related kernel errors and avoiding configurations that trigger mlx5e post action rules may reduce risk.


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