# CVE-2022-50881: wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect()

> A use-after-free in the ath9k USB Wi-Fi driver allows local attackers to execute arbitrary code or escalate privileges via physical USB access.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2022-50881, GHSA-wwq2-v7qh-cg3r, UBUNTU-CVE-2022-50881

## What is CVE-2022-50881?

CVE-2022-50881 is an 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:

wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect()

This patch fixes a use-after-free in ath9k that occurs in
ath9k_hif_usb_disconnect() when ath9k_destroy_wmi() is trying to access
'drv_priv' that has already been freed by ieee80211_free_hw(), called by
ath9k_htc_hw_deinit(). The patch moves ath9k_destroy_wmi() before
ieee80211_free_hw(). Note that urbs from the driver should be killed
before freeing 'wmi' with ath9k_destroy_wmi() as their callbacks will
access 'wmi'.

Found by a modified version of syzkaller.

==================================================================
BUG: KASAN: use-after-free in ath9k_destroy_wmi+0x38/0x40
Read of size 8 at addr ffff8881069132a0 by task kworker/0:1/7

CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #131
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: usb_hub_wq hub_event
Call Trace:
 dump_stack_lvl+0x8e/0xd1
 print_address_description.constprop.0.cold+0x93/0x334
 ? ath9k_destroy_wmi+0x38/0x40
 ? ath9k_destroy_wmi+0x38/0x40
 kasan_report.cold+0x83/0xdf
 ? ath9k_destroy_wmi+0x38/0x40
 ath9k_destroy_wmi+0x38/0x40
 ath9k_hif_usb_disconnect+0x329/0x3f0
 ? ath9k_hif_usb_suspend+0x120/0x120
 ? usb_disable_interface+0xfc/0x180
 usb_unbind_interface+0x19b/0x7e0
 ? usb_autoresume_device+0x50/0x50
 device_release_driver_internal+0x44d/0x520
 bus_remove_device+0x2e5/0x5a0
 device_del+0x5b2/0xe30
 ? __device_link_del+0x370/0x370
 ? usb_remove_ep_devs+0x43/0x80
 ? remove_intf_ep_devs+0x112/0x1a0
 usb_disable_device+0x1e3/0x5a0
 usb_disconnect+0x267/0x870
 hub_event+0x168d/0x3950
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? hub_port_debounce+0x2e0/0x2e0
 ? check_irq_usage+0x860/0xf20
 ? drain_workqueue+0x281/0x360
 ? lock_release+0x640/0x640
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x92b/0x1460
 ? pwq_dec_nr_in_flight+0x330/0x330
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x95/0xe00
 ? __kthread_parkme+0x115/0x1e0
 ? process_one_work+0x1460/0x1460
 kthread+0x3a1/0x480
 ? set_kthread_struct+0x120/0x120
 ret_from_fork+0x1f/0x30

The buggy address belongs to the page:
page:ffffea00041a44c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106913
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 7, ts 38347963444, free_ts 41399957635
 prep_new_page+0x1aa/0x240
 get_page_from_freelist+0x159a/0x27c0
 __alloc_pages+0x2da/0x6a0
 alloc_pages+0xec/0x1e0
 kmalloc_order+0x39/0xf0
 kmalloc_order_trace+0x19/0x120
 __kmalloc+0x308/0x390
 wiphy_new_nm+0x6f5/0x1dd0
 ieee80211_alloc_hw_nm+0x36d/0x2230
 ath9k_htc_probe_device+0x9d/0x1e10
 ath9k_htc_hw_init+0x34/0x50
 ath9k_hif_usb_firmware_cb+0x25f/0x4e0
 request_firmware_work_func+0x131/0x240
 process_one_work+0x92b/0x1460
 worker_thread+0x95/0xe00
 kthread+0x3a1/0x480
page last free stack trace:
 free_pcp_prepare+0x3d3/0x7f0
 free_unref_page+0x1e/0x3d0
 device_release+0xa4/0x240
 kobject_put+0x186/0x4c0
 put_device+0x20/0x30
 ath9k_htc_disconnect_device+0x1cf/0x2c0
 ath9k_htc_hw_deinit+0x26/0x30
 ath9k_hif_usb_disconnect+0x2d9/0x3f0
 usb_unbind_interface+0x19b/0x7e0
 device_release_driver_internal+0x44d/0x520
 bus_remove_device+0x2e5/0x5a0
 device_del+0x5b2/0xe30
 usb_disable_device+0x1e3/0x5a0
 usb_disconnect+0x267/0x870
 hub_event+0x168d/0x3950
 process_one_work+0x92b/0x1460

Memory state around the buggy address:
 ffff888106913180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888106913200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888
---truncated---

## Which versions are affected by CVE-2022-50881?


## How do I fix CVE-2022-50881?

Apply the vendor's patch.

## Is CVE-2022-50881 being exploited?

There is no known exploitation of CVE-2022-50881 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50881 and fix it if it is affected.

What it is: CVE-2022-50881 is an 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.
Exploitation: There is no known exploitation of CVE-2022-50881 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-2022-50881/ (Markdown: https://insights.sbomify.com/CVE-2022-50881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50881
- OSV: https://osv.dev/vulnerability/CVE-2022-50881

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50881/
Summaries are generated and may contain mistakes; the official description above is the record.
