CVE-2022-49315 Information

Description

In the Linux kernel the following vulnerability has been resolved:

drivers: staging: rtl8192e: Fix deadlock in rtllib_beacons_stop()

There is a deadlock in rtllib_beacons_stop() which is shown below:

(Thread 1) | (Thread 2) | rtllib_send_beacon() rtllib_beacons_stop() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) … | rtllib_send_beacon_cb() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | …

We hold ieee->beacon_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop but timer handler also need ieee->beacon_lock in position (2) of thread 2. As a result rtllib_beacons_stop() will block forever.

This patch extracts del_timer_sync() from the protection of spin_lock_irqsave() which could let timer handler to obtain the needed lock.

Reference

https://git.kernel.org/stable/c/08bacf871c019163ccd1389d0bc957a43324967a https://git.kernel.org/stable/c/0f69d7d5e918aa43423d86bd17ddb11b1b5e8ada https://git.kernel.org/stable/c/381045dc64d23a2229c47c5524c06bfc33d34446 https://git.kernel.org/stable/c/4681129fda9e8555392eaaadb239ec6a6e2b3e12 https://git.kernel.org/stable/c/46c861009bf437a18417df24cea0d181741b7d72 https://git.kernel.org/stable/c/64b05fa212c7e4d057676e8b7e7120c6eb2f615b https://git.kernel.org/stable/c/9b6bdbd9337de3917945847bde262a34a87a6303 https://git.kernel.org/stable/c/fef451f0fbbe85dbd2962b18379d02e2965610db https://git.kernel.org/stable/c/ffd4c4d5293e4985092ea45ba21cad9326e2e434