# CVE-2022-50726: net/mlx5: Fix possible use-after-free in async command interface
> A race condition in the Linux kernel mlx5 driver allows a use-after-free, potentially leading to code execution or system crashes.
- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-50726, GHSA-gjhx-8fr4-rcc6, UBUNTU-CVE-2022-50726
## What is CVE-2022-50726?
CVE-2022-50726 is a high-severity 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/mlx5: Fix possible use-after-free in async command interface
mlx5_cmd_cleanup_async_ctx should return only after all its callback
handlers were completed. Before this patch, the below race between
mlx5_cmd_cleanup_async_ctx and mlx5_cmd_exec_cb_handler was possible and
lead to a use-after-free:
1. mlx5_cmd_cleanup_async_ctx is called while num_inflight is 2 (i.e.
elevated by 1, a single inflight callback).
2. mlx5_cmd_cleanup_async_ctx decreases num_inflight to 1.
3. mlx5_cmd_exec_cb_handler is called, decreases num_inflight to 0 and
is about to call wake_up().
4. mlx5_cmd_cleanup_async_ctx calls wait_event, which returns
immediately as the condition (num_inflight == 0) holds.
5. mlx5_cmd_cleanup_async_ctx returns.
6. The caller of mlx5_cmd_cleanup_async_ctx frees the mlx5_async_ctx
object.
7. mlx5_cmd_exec_cb_handler goes on and calls wake_up() on the freed
object.
Fix it by syncing using a completion object. Mark it completed when
num_inflight reaches 0.
Trace:
BUG: KASAN: use-after-free in do_raw_spin_lock+0x23d/0x270
Read of size 4 at addr ffff888139cd12f4 by task swapper/5/0
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 6.0.0-rc3_for_upstream_debug_2022_08_30_13_10 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x7d
print_report.cold+0x2d5/0x684
? do_raw_spin_lock+0x23d/0x270
kasan_report+0xb1/0x1a0
? do_raw_spin_lock+0x23d/0x270
do_raw_spin_lock+0x23d/0x270
? rwlock_bug.part.0+0x90/0x90
? __delete_object+0xb8/0x100
? lock_downgrade+0x6e0/0x6e0
_raw_spin_lock_irqsave+0x43/0x60
? __wake_up_common_lock+0xb9/0x140
__wake_up_common_lock+0xb9/0x140
? __wake_up_common+0x650/0x650
? destroy_tis_callback+0x53/0x70 [mlx5_core]
? kasan_set_track+0x21/0x30
? destroy_tis_callback+0x53/0x70 [mlx5_core]
? kfree+0x1ba/0x520
? do_raw_spin_unlock+0x54/0x220
mlx5_cmd_exec_cb_handler+0x136/0x1a0 [mlx5_core]
? mlx5_cmd_cleanup_async_ctx+0x220/0x220 [mlx5_core]
? mlx5_cmd_cleanup_async_ctx+0x220/0x220 [mlx5_core]
mlx5_cmd_comp_handler+0x65a/0x12b0 [mlx5_core]
? dump_command+0xcc0/0xcc0 [mlx5_core]
? lockdep_hardirqs_on_prepare+0x400/0x400
? cmd_comp_notifier+0x7e/0xb0 [mlx5_core]
cmd_comp_notifier+0x7e/0xb0 [mlx5_core]
atomic_notifier_call_chain+0xd7/0x1d0
mlx5_eq_async_int+0x3ce/0xa20 [mlx5_core]
atomic_notifier_call_chain+0xd7/0x1d0
? irq_release+0x140/0x140 [mlx5_core]
irq_int_handler+0x19/0x30 [mlx5_core]
__handle_irq_event_percpu+0x1f2/0x620
handle_irq_event+0xb2/0x1d0
handle_edge_irq+0x21e/0xb00
__common_interrupt+0x79/0x1a0
common_interrupt+0x78/0xa0
asm_common_interrupt+0x22/0x40
RIP: 0010:default_idle+0x42/0x60
Code: c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 04 84 d2 75 14 8b 05 eb 47 22 02 85 c0 7e 07 0f 00 2d e0 9f 48 00 fb f4 48 c7 c7 80 08 7f 85 e8 d1 d3 3e fe eb de 66 66 2e 0f 1f 84 00
RSP: 0018:ffff888100dbfdf0 EFLAGS: 00000242
RAX: 0000000000000001 RBX: ffffffff84ecbd48 RCX: 1ffffffff0afe110
RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffff835cc9bc
RBP: 0000000000000005 R08: 0000000000000001 R09: ffff88881dec4ac3
R10: ffffed1103bd8958 R11: 0000017d0ca571c9 R12: 0000000000000005
R13: ffffffff84f024e0 R14: 0000000000000000 R15: dffffc0000000000
? default_idle_call+0xcc/0x450
default_idle_call+0xec/0x450
do_idle+0x394/0x450
? arch_cpu_idle_exit+0x40/0x40
? do_idle+0x17/0x450
cpu_startup_entry+0x19/0x20
start_secondary+0x221/0x2b0
? set_cpu_sibling_map+0x2070/0x2070
secondary_startup_64_no_verify+0xcd/0xdb
Allocated by task 49502:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0x81/0xa0
kvmalloc_node+0x48/0xe0
mlx5e_bulk_async_init+0x35/0x110 [mlx5_core]
mlx5e_tls_priv_tx_list_cleanup+0x84/0x3e0 [mlx5_core]
mlx5e_ktls_cleanup_tx+0x38f/0x760 [mlx5_core]
mlx5e_cleanup_nic_tx+0xa7/0x100 [mlx5_core]
mlx5e_detach_netdev+0x1c
---truncated---
## Which versions are affected by CVE-2022-50726?
## How do I fix CVE-2022-50726?
Apply the vendor's patch.
## Is CVE-2022-50726 being exploited?
There is no known exploitation of CVE-2022-50726 in the wild and no public exploit code.
## Fix prompt for AI coding agents
```text
Check this codebase for CVE-2022-50726 and fix it if it is affected.
What it is: CVE-2022-50726 is a high-severity 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.
Exploitation: There is no known exploitation of CVE-2022-50726 in the wild and no public exploit code.
Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2022-50726/ (Markdown: https://insights.sbomify.com/CVE-2022-50726/index.md)
```
## Sources
- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50726
- OSV: https://osv.dev/vulnerability/CVE-2022-50726
---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50726/
Summaries are generated and may contain mistakes; the official description above is the record.