Linux Kernel ext4 Directory Rename Vulnerability Leading to Crash

A vulnerability in the Linux kernel's ext4 file system can cause a crash when renaming directories. The issue arises because the '..' entry in the moved directory is not properly updated, allowing the renamed directory to be modified or converted from an inline format to a normal format. This can create a race condition that confuses the rename process, leading to a crash. The vulnerability has been addressed by locking the moved directory during the rename operation.

Impact

The vulnerability can lead to a system crash, causing a denial of service.