# CVE-2025-21729: wifi: rtw89: fix race between cancel_hw_scan and hw_scan completion

> A race condition in the rtw89 WiFi driver causes a use-after-free, potentially leading to system crashes or arbitrary code execution.

- **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:** 27 Feb 2025
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2025-21729, DEBIAN-CVE-2025-21729, GHSA-pc9x-vqhx-p2xg, ROOT-OS-DEBIAN-12-CVE-2025-21729, ROOT-OS-UBUNTU-2404-CVE-2025-21729, UBUNTU-CVE-2025-21729

## What is CVE-2025-21729?

CVE-2025-21729 is a high-severity use after free vulnerability in Linux kernel, published on 27 Feb 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:

wifi: rtw89: fix race between cancel_hw_scan and hw_scan completion

The rtwdev->scanning flag isn't protected by mutex originally, so
cancel_hw_scan can pass the condition, but suddenly hw_scan completion
unset the flag and calls ieee80211_scan_completed() that will free
local->hw_scan_req. Then, cancel_hw_scan raises null-ptr-deref and
use-after-free. Fix it by moving the check condition to where
protected by mutex.

 KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
 CPU: 2 PID: 6922 Comm: kworker/2:2 Tainted: G           OE
 Hardware name: LENOVO 2356AD1/2356AD1, BIOS G7ETB6WW (2.76 ) 09/10/2019
 Workqueue: events cfg80211_conn_work [cfg80211]
 RIP: 0010:rtw89_fw_h2c_scan_offload_be+0xc33/0x13c3 [rtw89_core]
 Code: 00 45 89 6c 24 1c 0f 85 23 01 00 00 48 8b 85 20 ff ff ff 48 8d
 RSP: 0018:ffff88811fd9f068 EFLAGS: 00010206
 RAX: dffffc0000000000 RBX: ffff88811fd9f258 RCX: 0000000000000001
 RDX: 0000000000000011 RSI: 0000000000000001 RDI: 0000000000000089
 RBP: ffff88811fd9f170 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff88811fd9f108 R11: 0000000000000000 R12: ffff88810e47f960
 R13: 0000000000000000 R14: 000000000000ffff R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff8881d6f00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007531dfca55b0 CR3: 00000001be296004 CR4: 00000000001706e0
 Call Trace:
  <TASK>
  ? show_regs+0x61/0x73
  ? __die_body+0x20/0x73
  ? die_addr+0x4f/0x7b
  ? exc_general_protection+0x191/0x1db
  ? asm_exc_general_protection+0x27/0x30
  ? rtw89_fw_h2c_scan_offload_be+0xc33/0x13c3 [rtw89_core]
  ? rtw89_fw_h2c_scan_offload_be+0x458/0x13c3 [rtw89_core]
  ? __pfx_rtw89_fw_h2c_scan_offload_be+0x10/0x10 [rtw89_core]
  ? do_raw_spin_lock+0x75/0xdb
  ? __pfx_do_raw_spin_lock+0x10/0x10
  rtw89_hw_scan_offload+0xb5e/0xbf7 [rtw89_core]
  ? _raw_spin_unlock+0xe/0x24
  ? __mutex_lock.constprop.0+0x40c/0x471
  ? __pfx_rtw89_hw_scan_offload+0x10/0x10 [rtw89_core]
  ? __mutex_lock_slowpath+0x13/0x1f
  ? mutex_lock+0xa2/0xdc
  ? __pfx_mutex_lock+0x10/0x10
  rtw89_hw_scan_abort+0x58/0xb7 [rtw89_core]
  rtw89_ops_cancel_hw_scan+0x120/0x13b [rtw89_core]
  ieee80211_scan_cancel+0x468/0x4d0 [mac80211]
  ieee80211_prep_connection+0x858/0x899 [mac80211]
  ieee80211_mgd_auth+0xbea/0xdde [mac80211]
  ? __pfx_ieee80211_mgd_auth+0x10/0x10 [mac80211]
  ? cfg80211_find_elem+0x15/0x29 [cfg80211]
  ? is_bss+0x1b7/0x1d7 [cfg80211]
  ieee80211_auth+0x18/0x27 [mac80211]
  cfg80211_mlme_auth+0x3bb/0x3e7 [cfg80211]
  cfg80211_conn_do_work+0x410/0xb81 [cfg80211]
  ? __pfx_cfg80211_conn_do_work+0x10/0x10 [cfg80211]
  ? __kasan_check_read+0x11/0x1f
  ? psi_group_change+0x8bc/0x944
  ? __kasan_check_write+0x14/0x22
  ? mutex_lock+0x8e/0xdc
  ? __pfx_mutex_lock+0x10/0x10
  ? __pfx___radix_tree_lookup+0x10/0x10
  cfg80211_conn_work+0x245/0x34d [cfg80211]
  ? __pfx_cfg80211_conn_work+0x10/0x10 [cfg80211]
  ? update_cfs_rq_load_avg+0x3bc/0x3d7
  ? sched_clock_noinstr+0x9/0x1a
  ? sched_clock+0x10/0x24
  ? sched_clock_cpu+0x7e/0x42e
  ? newidle_balance+0x796/0x937
  ? __pfx_sched_clock_cpu+0x10/0x10
  ? __pfx_newidle_balance+0x10/0x10
  ? __kasan_check_read+0x11/0x1f
  ? psi_group_change+0x8bc/0x944
  ? _raw_spin_unlock+0xe/0x24
  ? raw_spin_rq_unlock+0x47/0x54
  ? raw_spin_rq_unlock_irq+0x9/0x1f
  ? finish_task_switch.isra.0+0x347/0x586
  ? __schedule+0x27bf/0x2892
  ? mutex_unlock+0x80/0xd0
  ? do_raw_spin_lock+0x75/0xdb
  ? __pfx___schedule+0x10/0x10
  process_scheduled_works+0x58c/0x821
  worker_thread+0x4c7/0x586
  ? __kasan_check_read+0x11/0x1f
  kthread+0x285/0x294
  ? __pfx_worker_thread+0x10/0x10
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x29/0x6f
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1b/0x30
  </TASK>

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-21729?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21729?

Apply the vendor's patch.

## Is CVE-2025-21729 being exploited?

There is no known exploitation of CVE-2025-21729 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21729 and fix it if it is affected.

What it is: CVE-2025-21729 is a high-severity use after free vulnerability in Linux kernel, published on 27 Feb 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-2025-21729 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2025-21729/ (Markdown: https://insights.sbomify.com/CVE-2025-21729/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21729
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21729
- OSV: https://osv.dev/vulnerability/CVE-2025-21729

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21729/
Summaries are generated and may contain mistakes; the official description above is the record.