CVE-2022-49112: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-49112 is a vulnerability in the Linux kernel affecting the mt7921s driver component. The vulnerability was discovered in 2022 and relates to monitor mode functionality in the SDIO driver.

The vulnerability occurs when the mt7921s driver receives frames with fragment buffers in monitor mode. Specifically, when a CTS packet is received in monitor mode with a 10-byte payload requiring 6 bytes of header padding after the RXD buffer, an issue arises because only RXD exists in the first linear buffer. When attempting to pull buffer size RXD-size+6 bytes with skb_pull(), it triggers a 'BUG_ON(skb->len < skb->data_len)' condition in __skb_pull() (Linux Kernel).

The vulnerability can cause a kernel crash when using monitor mode with the mt7921s SDIO driver, potentially leading to system instability and denial of service conditions.

The vulnerability is triggered specifically in monitor mode operation of the mt7921s driver when processing certain types of network packets. It requires the affected device to be operating in monitor mode to be exploitable.

The fix involves enlarging the RXD size from 128 to 256 bytes to ensure all MCU operations remain in the linear buffer, preventing the nonlinear buffer issue. This was implemented through a patch to the Linux kernel (Linux Kernel).