CVE-2026-31598

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: fix possible deadlock between unlink and dioendio_write

ocfs2unlink takes orphan dir inodelock first and then ipallocsem, while in ocfs2dioendiowrite, it acquires these locks in reverse order. This creates an ABBA lock ordering violation on lock classes ocfs2sysfilelockkey[ORPHANDIRSYSTEMINODE] and ocfs2fileipallocsem_key.

Lock Chain #0 (orphan dir inodelock -> ipallocsem): ocfs2unlink ocfs2prepareorphandir ocfs2lookuplockorphandir inodelock(orphandirinode) <- lock A _ocfs2prepareorphandir ocfs2preparedirforinsert ocfs2extenddir ocfs2expandinlinedir downwrite(&oi->ipallocsem) <- Lock B

Lock Chain #1 (ipallocsem -> orphan dir inodelock): ocfs2dioendiowrite downwrite(&oi->ipallocsem) <- Lock B ocfs2delinodefromorphan() inodelock(orphandir_inode) <- Lock A

Deadlock Scenario: CPU0 (unlink) CPU1 (dioendiowrite) ------ ------ inodelock(orphandirinode) downwrite(ipallocsem) downwrite(ipallocsem) inodelock(orphandir_inode)

Since ipallocsem is to protect allocation changes, which is unrelated with operations in ocfs2delinodefromorphan. So move ocfs2delinodefromorphan out of ipallocsem to fix the deadlock.