cbcvebase.
CVE-2026-23036
published 2026-01-31

CVE-2026-23036: In the Linux kernel, the following vulnerability has been resolved: btrfs: release path before iget_failed() in btrfs_read_locked_inode() In…

PriorityP420low5.5
EPSS
0.19%
9.4th percentile
In the Linux kernel, the following vulnerability has been resolved: btrfs: release path before iget_failed() in btrfs_read_locked_inode() In btrfs_read_locked_inode() if we fail to lookup the inode, we jump to the 'out' label with a path that has a read locked leaf and then we call iget_failed(). This can result in a ABBA deadlock, since iget_failed() triggers inode eviction and that causes the release of the delayed inode, which must lock the delayed inode's mutex, and a task updating a delayed inode starts by taking the node's mutex and then modifying the inode's subvolume btree. Syzbot reported the following lockdep splat for this: WARNING: possible circular locking dependency detected syzkaller #0 Not tainted btrfs-cleaner/8725 is trying to acquire lock: ffff0000d6826a48 (&delayed_node->mutex){+.+.}-{4:4}, at: __btrfs_release_delayed_node+0xa0/0x9b0 fs/btrfs/delayed-inode.c:290 but task is already holding lock: ffff0000dbeba878 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x44/0x2ec fs/btrfs/locking.c:145 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-tree-00){++++}-{4:4}: __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x198/0x39c kernel/locking/lockdep.c:5889 up_read+0x24/0x3c kernel/locking/rwsem.c:1632 btrfs_tree_read_unlock+0xdc/0x298 fs/btrfs/locking.c:169 btrfs_tree_unlock_rw fs/btrfs/locking.h:218 [inline] btrfs_search_slot+0xa6c/0x223c fs/btrfs/ctree.c:2133 btrfs_lookup_inode+0xd8/0x38c fs/btrfs/inode-item.c:395 __btrfs_update_delayed_inode+0x124/0xed0 fs/btrfs/delayed-inode.c:1032 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1118 [inline] __btrfs_commit_inode_delayed_items+0x15f8/0x1748 fs/btrfs/delayed-inode.c:1141 __btrfs_run_delayed_items+0x1ac/0x514 fs/btrfs/delayed-inode.c:1176 btrfs_run_delayed_items_nr+0x28/0x38 fs/btrfs/delayed-inode.c:1219 flush_space+0x26c/0xb68 fs/btrfs/space-info.c:828 do_async_reclaim_metadata_space+0x110/0x364

Affected

12 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.8-1 (forky)linux 6.18.8-1 (forky)
linuxlinux
linuxlinux>= 69673992b1aea5540199d9b8b658ede72f55a6cf < 65241e3ddda60b53a4ee3ae12721fc9ee21d582765241e3ddda60b53a4ee3ae12721fc9ee21d5827
linuxlinux>= 69673992b1aea5540199d9b8b658ede72f55a6cf < 1e1f2055ad5a7a5d548789b334a4473a7665c4181e1f2055ad5a7a5d548789b334a4473a7665c418
linuxlinux_kernel>= 0 < 6.18.8-16.18.8-1
linuxlinux_kernel>= 6.13.0 < 6.18.76.18.7
ubuntulinux-azure-6.17
ubuntulinux-azure-fde-6.17
ubuntulinux-gcp-6.17
ubuntulinux-oem-6.17
ubuntulinux-oracle-6.17
ubuntulinux-realtime-6.17
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