CVE-2021-47163

This linux kernel vulnerability occurs in the TIPC (Transparent Inter-Process Communication) networking module, specifically concerning how background tasks are handled during module removal. The issue arises when the TIPC module is being unloaded while a UDP tunnel socket is still delayed for release within a scheduled work queue. If this delayed cleanup task executes after the module has already been removed from the system, the kernel attempts to invoke a cleanup function that no longer exists in memory, resulting in a paging request failure and a subsequent kernel crash. Patched kernel versions resolve the issue by introducing a tracking mechanism that forces the system to explicitly wait until all pending work queues have successfully finished their tasks before allowing the TIPC module to safely exit.

This vulnerability is rated as Low impact because triggering it requires local administrative privileges to configure network bearers and unload kernel modules, limiting the risk primarily to a system denial of service. The TIPC protocol is not loaded by default in standard Red Hat Enterprise Linux installations. Systems that do not utilize TIPC or dynamically unload the module are not exposed during normal operations.

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.