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 fs/btrfs/space-info.c:1158 btrfs_async_reclaim_metadata_space+0x90/0xd8 fs/btrfs/space-info.c:1226 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 -> #0 (&delayed_node->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 __btrfs_release_delayed_node+0xa0/0x9b0 fs/btrfs/delayed-inode.c:290 btrfs_release_delayed_node fs/btrfs/delayed-inode.c:315 [inline] btrfs_remove_delayed_node+0x68/0x84 fs/btrfs/delayed-inode.c:1326 btrfs_evict_inode+0x578/0xe28 fs/btrfs/inode.c:5587 evict+0x414/0x928 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput+0x95c/0xad4 fs/inode.c:1966 iget_failed+0xec/0x134 fs/bad_inode.c:248 btrfs_read_locked_inode+0xe1c/0x1234 fs/btrfs/inode.c:4101 btrfs_iget+0x1b0/0x264 fs/btrfs/inode.c:5837 btrfs_run_defrag_inode fs/btrfs/defrag.c:237 [inline] btrfs_run_defrag_inodes+0x520/0xdc4 fs/btrf ---truncated---

The remote Ubuntu 24.04 LTS / Pro Realtime 24.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8669-1 advisory.

    Several security issues were discovered in the Linux kernel. An attacker could possibly use these to     compromise the system. This update corrects flaws in the following subsystems:

    - Foo-over-UDP (FOU);

    - ARM64 architecture;

    - x86 architecture;

    - Block layer subsystem;

    - Drivers core;

    - Null block device driver;

    - Bluetooth drivers;

    - Counter interface drivers;

    - DMA engine subsystem;

    - DPLL subsystem;

    - GPIO subsystem;

    - GPU drivers;

    - I2C subsystem;

    - IIO ADC drivers;

    - IIO subsystem;

    - InfiniBand drivers;

    - On-Chip Interconnect management framework;

    - IOMMU subsystem;

    - IRQ chip drivers;

    - Modular ISDN driver;

    - LED subsystem;

    - Multiple devices driver;

    - Media drivers;

    - UACCE accelerator framework;

    - MMC subsystem;

    - Ethernet bonding driver;

    - Network drivers;

    - Mellanox network drivers;

    - Texas Instruments network drivers;

    - NVME drivers;

    - Device tree and open firmware driver;

    - PHY drivers;

    - x86 platform drivers;

    - i.MX PM domains;

    - SCSI subsystem;

    - SLIMbus drivers;

    - SPI subsystem;

    - TTY drivers;

    - USB Host Controller drivers;

    - W1 Dallas's 1-wire bus driver;

    - Xen hypervisor drivers;

    - BTRFS file system;

    - EFI Variable file system;

    - File systems infrastructure;

    - Ext4 file system;

    - FUSE (File system in Userspace);

    - Network file systems library;

    - Network file system (NFS) client;

    - Network file system (NFS) server daemon;

    - SMB network file system;

    - Memory Management;

    - Memory management;

    - Scheduler infrastructure;

    - Tracing infrastructure;

    - IPv4 networking;

    - Netfilter;

    - NFC subsystem;

    - Network traffic control;

    - TCP network protocol;

    - io_uring subsystem;

    - Perf events;

    - Locking primitives;

    - Hibernation control;

    - Timer subsystem;

    - BPF subsystem;

    - Floating proportions library;

    - Bluetooth subsystem;

    - CAN network layer;

    - Ceph Core library;

    - Networking core;

    - IPv6 networking;

    - L2TP protocol;

    - MAC80211 subsystem;

    - Multipath TCP;

    - NET/ROM layer;

    - RxRPC session sockets;

    - SCTP protocol;

    - SMC sockets;

    - VMware vSockets driver;

    - Wireless networking;

    - ALSA AC97 driver;

    - Creative Sound Blaster X-Fi driver;

    - Texas InstrumentS Audio (ASoC/HDA) drivers;

    - USB sound devices; (CVE-2025-71158, CVE-2025-71160, CVE-2025-71161, CVE-2025-71162, CVE-2025-71163,     CVE-2025-71180, CVE-2025-71182, CVE-2025-71183, CVE-2025-71184, CVE-2025-71185, CVE-2025-71186,     CVE-2025-71187, CVE-2025-71188, CVE-2025-71189, CVE-2025-71190, CVE-2025-71191, CVE-2025-71192,     CVE-2025-71193, CVE-2025-71194, CVE-2025-71195, CVE-2025-71196, CVE-2025-71197, CVE-2025-71198,     CVE-2025-71199, CVE-2025-71200, CVE-2025-71201, CVE-2026-22976, CVE-2026-22977, CVE-2026-22978,     CVE-2026-22979, CVE-2026-22980, CVE-2026-22981, CVE-2026-22982, CVE-2026-22985, CVE-2026-22986,     CVE-2026-22987, CVE-2026-22989, CVE-2026-22990, CVE-2026-22991, CVE-2026-22992, CVE-2026-22993,     CVE-2026-22994, CVE-2026-22996, CVE-2026-22997, CVE-2026-22998, CVE-2026-22999, CVE-2026-23000,     CVE-2026-23001, CVE-2026-23002, CVE-2026-23003, CVE-2026-23004, CVE-2026-23005, CVE-2026-23006,     CVE-2026-23007, CVE-2026-23008, CVE-2026-23009, CVE-2026-23010, CVE-2026-23011, CVE-2026-23012,     CVE-2026-23013, CVE-2026-23014, CVE-2026-23015, CVE-2026-23017, CVE-2026-23018, CVE-2026-23019,     CVE-2026-23020, CVE-2026-23021, CVE-2026-23022, CVE-2026-23023, CVE-2026-23024, CVE-2026-23025,     CVE-2026-23026, CVE-2026-23030, CVE-2026-23031, CVE-2026-23032, CVE-2026-23033, CVE-2026-23034,     CVE-2026-23035, CVE-2026-23036, CVE-2026-23037, CVE-2026-23038, CVE-2026-23042, CVE-2026-23044,     CVE-2026-23045, CVE-2026-23046, CVE-2026-23047, CVE-2026-23049, CVE-2026-23050, CVE-2026-23051,     CVE-2026-23052, CVE-2026-23053, CVE-2026-23054, CVE-2026-23055, CVE-2026-23056, CVE-2026-23057,     CVE-2026-23058, CVE-2026-23059, CVE-2026-23061, CVE-2026-23062, CVE-2026-23063, CVE-2026-23064,     CVE-2026-23065, CVE-2026-23066, CVE-2026-23067, CVE-2026-23068, CVE-2026-23069, CVE-2026-23070,     CVE-2026-23071, CVE-2026-23072, CVE-2026-23073, CVE-2026-23075, CVE-2026-23076, CVE-2026-23077,     CVE-2026-23078, CVE-2026-23079, CVE-2026-23080, CVE-2026-23081, CVE-2026-23083, CVE-2026-23084,     CVE-2026-23085, CVE-2026-23086, CVE-2026-23087, CVE-2026-23088, CVE-2026-23089, CVE-2026-23090,     CVE-2026-23092, CVE-2026-23093, CVE-2026-23094, CVE-2026-23095, CVE-2026-23096, CVE-2026-23097,     CVE-2026-23098, CVE-2026-23099, CVE-2026-23100, CVE-2026-23101, CVE-2026-23102, CVE-2026-23103,     CVE-2026-23104, CVE-2026-23105, CVE-2026-23106, CVE-2026-23107, CVE-2026-23108, CVE-2026-23109,     CVE-2026-23110, CVE-2026-23113, CVE-2026-23114, CVE-2026-23115, CVE-2026-23116, CVE-2026-23118,     CVE-2026-23119, CVE-2026-23120, CVE-2026-23121, CVE-2026-23122, CVE-2026-23123, CVE-2026-23124,     CVE-2026-23125, CVE-2026-23126, CVE-2026-23128, CVE-2026-23129, CVE-2026-23130, CVE-2026-23131,     CVE-2026-23133, CVE-2026-23135, CVE-2026-23136, CVE-2026-23137, CVE-2026-23138, CVE-2026-23139,     CVE-2026-23140, CVE-2026-23141, CVE-2026-23142, CVE-2026-23143, CVE-2026-23144, CVE-2026-23145,     CVE-2026-23146, CVE-2026-23147, CVE-2026-23148, CVE-2026-23150, CVE-2026-23151, CVE-2026-23152,     CVE-2026-23154, CVE-2026-23156, CVE-2026-23157, CVE-2026-23158, CVE-2026-23159, CVE-2026-23160,     CVE-2026-23161, CVE-2026-23162, CVE-2026-23163, CVE-2026-23164, CVE-2026-23165, CVE-2026-23166,     CVE-2026-23167, CVE-2026-23168, CVE-2026-23169, CVE-2026-23170, CVE-2026-23171, CVE-2026-23172,     CVE-2026-23173, CVE-2026-23212, CVE-2026-31405, CVE-2026-31414, CVE-2026-31444, CVE-2026-31501,     CVE-2026-31589, CVE-2026-31633, CVE-2026-31636, CVE-2026-31705, CVE-2026-43198, CVE-2026-43379,     CVE-2026-43465, CVE-2026-43499, CVE-2026-46113, CVE-2026-46137, CVE-2026-46242, CVE-2026-46290,     CVE-2026-46317, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53131,     CVE-2026-53176, CVE-2026-53212, CVE-2026-53225, CVE-2026-53228, CVE-2026-53277, CVE-2026-53359)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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 fs/btrfs/space-info.c:1158     btrfs_async_reclaim_metadata_space+0x90/0xd8 fs/btrfs/space-info.c:1226 process_one_work+0x7e8/0x155c     kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8     kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20     arch/arm64/kernel/entry.S:844 -> #0 (&delayed_node->mutex){+.+.}-{4:4}: check_prev_add     kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline]     validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1774/0x30a4     kernel/locking/lockdep.c:5237 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
    __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760     [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 __btrfs_release_delayed_node+0xa0/0x9b0     fs/btrfs/delayed-inode.c:290 btrfs_release_delayed_node fs/btrfs/delayed-inode.c:315 [inline]     btrfs_remove_delayed_node+0x68/0x84 fs/btrfs/delayed-inode.c:1326 btrfs_evict_inode+0x578/0xe28     fs/btrfs/inode.c:5587 evict+0x414/0x928 fs/inode.c:810 iput_final fs/inode.c:1914 [inline]     iput+0x95c/0xad4 fs/inode.c:1966 iget_failed+0xec/0x134 fs/bad_inode.c:248     btrfs_read_locked_inode+0xe1c/0x1234 fs/btrfs/inode.c:4101 btrfs_iget+0x1b0/0x264 fs/btrfs/inode.c:5837     btrfs_run_defrag_inode fs/btrfs/defrag.c:237 [inline] btrfs_run_defrag_inodes+0x520/0xdc4 fs/btrf
    ---truncated--- (CVE-2026-23036)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
340678	Ubuntu 24.04 LTS / Pro Realtime 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8669-1)	Nessus	Ubuntu Local Security Checks	Local	high
335080	openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21555-1)	Nessus	SuSE Local Security Checks	Local	high
297489	Linux Distros Unpatched Vulnerability : CVE-2026-23036	Nessus	Misc.	Local	medium

Detections

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CVE-2026-23036

medium

Tenable Plugins

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high

medium