Linux Kernel PCI Bridge Check Vulnerability in rtw88 WiFi Driver

A vulnerability in the Linux kernel's rtw88 WiFi driver can cause a system crash when the 8821CE device is installed on a root bus without a PCI-to-PCI bridge. The issue arises because the probing routine fails to find the necessary bridge, leading to a crash. This vulnerability has likely gone unnoticed, as the 8821CE is typically used in laptops with the appropriate PCI bridge configuration. However, it can be installed on systems with different PCI topologies, where the bridge is absent, causing the probing routine to crash. The vulnerability was identified by the Linux Verification Center using the Svace static analysis tool.

Impact

The vulnerability can cause a system crash by disrupting the probing routine of the rtw88 WiFi driver when the 8821CE device is installed on a root bus without an upstream PCI bridge.

Remediation

Users can check for the existence of a PCI upstream bridge and apply the specific workaround if needed. The Linux kernel has been patched to address this vulnerability, and the fixed version can be downloaded from the Linux kernel stable tree.