CVE-2022-50714

A flaw was discovered in the mt76/mt7921e Wi-Fi driver in the Linux kernel where improper handling of driver data during module removal can lead to a crash. Under certain insmod/rmmod stress test conditions, the driver’s mt7921_pci_remove() function is called while the associated mt76_dev (driver private data) has not been properly initialized or is missing. When the workqueue cancellation logic attempts to access this uninitialized data, it triggers a KASAN BUG: user-memory-access, resulting in a kernel panic or hang.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, if the mt7921e Wi-Fi hardware is not in use, prevent the mt7921e kernel module from loading. This can be achieved by blacklisting the module.

Create a file named /etc/modprobe.d/blacklist-mt7921e.conf with the following content:

blacklist mt7921e

After creating the file, regenerate the initramfs and reboot the system for the changes to take effect:

dr_acutereboot

Warning: Blacklisting this module may disable Wi-Fi functionality if your system relies on the mt7921e driver.