CVE-2022-50740 wifi: ath9k: hif_usb: fix memory leak of urbs in ath9k_hif_usb_dealloc_tx_urbs()
A memory leak in the ath9k USB WiFi driver allows local attackers to cause a denial of service by exhausting kernel memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50740?
CVE-2022-50740 is a memory corruption 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:
wifi: ath9k: hif_usb: fix memory leak of urbs in ath9k_hif_usb_dealloc_tx_urbs()
Syzkaller reports a long-known leak of urbs in ath9k_hif_usb_dealloc_tx_urbs().
The cause of the leak is that usb_get_urb() is called but usb_free_urb() (or usb_put_urb()) is not called inside usb_kill_urb() as urb->dev or urb->ep fields have not been initialized and usb_kill_urb() returns immediately.
The patch removes trying to kill urbs located in hif_dev->tx.tx_buf because hif_dev->tx.tx_buf is not supposed to contain urbs which are in pending state (the pending urbs are stored in hif_dev->tx.tx_pending). The tx.tx_lock is acquired so there should not be any changes in the list.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Which versions are affected by CVE-2022-50740?
How do I fix CVE-2022-50740?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-50740 being exploited?
There is no known exploitation of CVE-2022-50740 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50740, GHSA-3fvr-fgq3-468j, UBUNTU-CVE-2022-50740.