Linux Kernel SMB Client NULL Pointer Dereference Vulnerability in Automount Path Handling

A vulnerability in the Linux kernel's SMB client has been addressed, which could lead to a NULL pointer dereference. The issue arises in the automount path handling, specifically in the function '__build_path_from_dentry_optional_prefix'. When the 'tcon->origin_fullpath' is not set, the full path page is correctly checked for NULL. However, this check is absent when the path is set, creating a potential vulnerability. The recent patch adds the necessary NULL check to prevent this issue.

Impact

Exploitation of this vulnerability could lead to a NULL pointer dereference, causing a crash or undefined behavior in the kernel.