Deadlock Vulnerability in Linux Kernel's SMB Server Functionality

CVE-2025-38711

What is CVE-2025-38711?

A deadlock vulnerability exists in the Linux Kernel's SMB server functionality that arises when the smb2_create_link() function is called with the ReplaceIfExists parameter set. When a link is created to an existing name, this leads to a deadlock situation as the parent directory gets locked during the link creation process. The locking mechanism fails because the function attempts to lock the parent directory again even while it is already locked, consequently resulting in a deadlock. A patch has been introduced to prevent this issue by rearranging the call order, ensuring that the parent directory is unlocked before attempting to create the link, thereby simplifying the code and improving its reliability.

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