Medium [CVE-2026-72187] avoid self-deadlock during inode eviction

In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid self-deadlock during inode eviction An attribute-list update performed while allocating clusters can drop the last reference to the temporary attribute inode.

Evicting that inode drops its reference to the base inode and can invoke ntfs_drop_big_inode() for the base inode from within the base inode's own writeback path. If the base inode is unlinked, ntfs_drop_big_inode() calls truncate_setsize(), which waits for the inode's folio writeback to complete.

The same writeback worker is responsible for completing that writeback, so it waits for itself indefinitely. Prevent this self-deadlock by grabbing a reference to the base inode at the beginning of ntfs_writepages() and releasing it at the end of the function.

This defers eviction until all bios have been submitted, allowing the wait for folio writeback to complete safely. A flaw was found in the Linux kernel's NTFS file system driver.

An attacker with local access could trigger a self-deadlock condition during inode eviction. This occurs when an attribute-list update during cluster allocation causes a temporary inode to lose its last reference, leading to an indefinite wait during writeback.

Successful exploitation of this vulnerability could result in a Denial of Service (DoS), causing the system to become unresponsive.