CVE-2026-80879

Summary

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

ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write

A circular locking dependency involves INODE_ALLOC_SYSTEM_INODE, EXTENT_ALLOC_SYSTEM_INODE, and ORPHAN_DIR_SYSTEM_INODE.

1. ocfs2_mknod() acquires INODE_ALLOC then EXTENT_ALLOC.

2. ocfs2_dio_end_io_write() acquires EXTENT_ALLOC for unwritten extents, then ORPHAN_DIR via ocfs2_del_inode_from_orphan() while still holding EXTENT_ALLOC.

3. ocfs2_wipe_inode() acquires ORPHAN_DIR then INODE_ALLOC via ocfs2_remove_inode.

Break the cycle in ocfs2_dio_end_io_write() by freeing the allocation contexts (releasing EXTENT_ALLOC) before acquiring ORPHAN_DIR.

WARNING: possible circular locking dependency detected

is trying to acquire lock: ffff8881e78b33a0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0x1539/0x43b0 fs/ocfs2/inode.c:1299

but task is already holding lock: ffff8881e78b4fa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x43b0 fs/ocfs2/inode.c:1299

the existing dependency chain (in reverse order) is:

-> #2 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}: inode_lock include/linux/fs.h:1029 [inline] ocfs2_del_inode_from_orphan+0x12e/0x7a0 fs/ocfs2/namei.c:2728 ocfs2_dio_end_io+0xf9c/0x1370 fs/ocfs2/aops.c:2418 dio_complete+0x25b/0x790 fs/direct-io.c:281

-> #1 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}: inode_lock include/linux/fs.h:1029 [inline] ocfs2_reserve_suballoc_bits+0x16d/0x4840 fs/ocfs2/suballoc.c:882 ocfs2_reserve_new_metadata_blocks+0x415/0x9a0 fs/ocfs2/suballoc.c:1078 ocfs2_mknod+0x10f3/0x2260 fs/ocfs2/namei.c:351

-> #0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}: __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 down_write+0x96/0x200 kernel/locking/rwsem.c:1625 inode_lock include/linux/fs.h:1029 [inline] ocfs2_remove_inode fs/ocfs2/inode.c:733 [inline] ocfs2_wipe_inode fs/ocfs2/inode.c:896 [inline] ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline] ocfs2_evict_inode+0x1539/0x43b0 fs/ocfs2/inode.c:1299

Chain exists of: &ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE] –> &ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE] –> &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]

Possible unsafe locking scenario:

   CPU0                    CPU1
   ----                    ----

lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]); lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]); lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]); lock(&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]);

*** DEADLOCK ***

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/f0ae0a6ca87dc2d4a789f71cdedb808ba6c16990
• https://git.kernel.org/stable/c/137e8b4823a9a11928428d4ec0a0cacb2f50a769
• https://git.kernel.org/stable/c/4273548e418bd935430d35e9d052870f323441f3
• https://git.kernel.org/stable/c/49b34bd3ad69611af03590a23abf2cda9ac1073d
• https://git.kernel.org/stable/c/ff187c502b39389b0d732cb7050a3db8e5ebfcd6
• https://git.kernel.org/stable/c/ae1f3460833d3e427420ab260278ec0e45d68c86
• https://git.kernel.org/stable/c/f3dd1e534e9de64669415f8239e0094afecfed78
• https://git.kernel.org/stable/c/ff6f26c58421614b02694ac9d219ac61d924bc68

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