Medium [CVE-2026-72189] fail attrlist updates when the superblock is inactive

In the Linux kernel, the following vulnerability has been resolved: ntfs: fail attrlist updates when the superblock is inactive generic_shutdown_super() clears SB_ACTIVE before evicting cached inodes.

If eviction selects the fake inode for a base inode's unnamed $ATTRIBUTE_LIST attribute, ntfs_evict_big_inode() drops the fake inode's reference on the base inode while the fake inode is still hashed and marked I_FREEING. That iput can synchronously write back the base inode.

The writeback path may update mapping pairs and call ntfs_attrlist_update(), which unconditionally calls ntfs_attr_iget() for the same $ATTRIBUTE_LIST fake inode. VFS then finds the I_FREEING inode and waits for eviction to finish, but the current task is still inside that eviction path, causing a self-deadlock in find_inode().

Fix this by mirroring the teardown guard used by __ntfs_write_inode(): once SB_ACTIVE has been cleared, do not try to iget the attribute-list fake inode. Return -EIO so teardown aborts the update instead of waiting on the inode it is evicting.

A flaw was found in the Linux kernel's NTFS file system. During the process of shutting down a file system, a specific internal condition can arise where the system attempts to update an attribute list while an associated inode is being evicted.