Linux Kernel NULL Pointer Dereference Vulnerability in netfs Cache Invalidation

A vulnerability in the Linux kernel's netfs component can lead to a NULL pointer dereference, causing a kernel crash. This issue arises in certain filesystems like NFS and Ceph, which do not implement the 'invalidate_cache' method. When writing to the cache fails, the absence of this method can trigger a crash by attempting to access a NULL pointer. The vulnerability has been addressed by adding a necessary NULL check before calling 'invalidate_cache'.

Impact

Exploitation of this vulnerability leads to a kernel crash due to a NULL pointer dereference.