{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23018 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23018 is a medium-severity vulnerability in Linux kernel, published on 31 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-23018 and fix it if it is affected.\n\nWhat it is: CVE-2026-23018 is a medium-severity vulnerability in Linux kernel, published on 31 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-23018 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-23018/ (Markdown: https://insights.sbomify.com/CVE-2026-23018/index.md)","id":"CVE-2026-23018","markdown":"https://insights.sbomify.com/CVE-2026-23018/index.md","name":"CVE-2026-23018","record":{"aliases":["BELL-CVE-2026-23018","DEBIAN-CVE-2026-23018","GHSA-9frx-88jj-qgh5","UBUNTU-CVE-2026-23018"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel filesystem","requires_auth":"low_privilege","summary":"A circular locking dependency in the btrfs filesystem can cause a deadlock during memory reclaim, leading to a system hang or denial of service.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: release path before initializing extent tree in btrfs_read_locked_inode()\n\nIn btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree()\nwhile holding a path with a read locked leaf from a subvolume tree, and\nbtrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can\ntrigger reclaim.\n\nThis can create a circular lock dependency which lockdep warns about with\nthe following splat:\n\n   [6.1433] ======================================================\n   [6.1574] WARNING: possible circular locking dependency detected\n   [6.1583] 6.18.0+ #4 Tainted: G     U\n   [6.1591] ------------------------------------------------------\n   [6.1599] kswapd0/117 is trying to acquire lock:\n   [6.1606] ffff8d9b6333c5b8 (\u0026delayed_node-\u003emutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0\n   [6.1625]\n            but task is already holding lock:\n   [6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60\n   [6.1646]\n            which lock already depends on the new lock.\n\n   [6.1657]\n            the existing dependency chain (in reverse order) is:\n   [6.1667]\n            -\u003e #2 (fs_reclaim){+.+.}-{0:0}:\n   [6.1677]        fs_reclaim_acquire+0x9d/0xd0\n   [6.1685]        __kmalloc_cache_noprof+0x59/0x750\n   [6.1694]        btrfs_init_file_extent_tree+0x90/0x100\n   [6.1702]        btrfs_read_locked_inode+0xc3/0x6b0\n   [6.1710]        btrfs_iget+0xbb/0xf0\n   [6.1716]        btrfs_lookup_dentry+0x3c5/0x8e0\n   [6.1724]        btrfs_lookup+0x12/0x30\n   [6.1731]        lookup_open.isra.0+0x1aa/0x6a0\n   [6.1739]        path_openat+0x5f7/0xc60\n   [6.1746]        do_filp_open+0xd6/0x180\n   [6.1753]        do_sys_openat2+0x8b/0xe0\n   [6.1760]        __x64_sys_openat+0x54/0xa0\n   [6.1768]        do_syscall_64+0x97/0x3e0\n   [6.1776]        entry_SYSCALL_64_after_hwframe+0x76/0x7e\n   [6.1784]\n            -\u003e #1 (btrfs-tree-00){++++}-{3:3}:\n   [6.1794]        lock_release+0x127/0x2a0\n   [6.1801]        up_read+0x1b/0x30\n   [6.1808]        btrfs_search_slot+0x8e0/0xff0\n   [6.1817]        btrfs_lookup_inode+0x52/0xd0\n   [6.1825]        __btrfs_update_delayed_inode+0x73/0x520\n   [6.1833]        btrfs_commit_inode_delayed_inode+0x11a/0x120\n   [6.1842]        btrfs_log_inode+0x608/0x1aa0\n   [6.1849]        btrfs_log_inode_parent+0x249/0xf80\n   [6.1857]        btrfs_log_dentry_safe+0x3e/0x60\n   [6.1865]        btrfs_sync_file+0x431/0x690\n   [6.1872]        do_fsync+0x39/0x80\n   [6.1879]        __x64_sys_fsync+0x13/0x20\n   [6.1887]        do_syscall_64+0x97/0x3e0\n   [6.1894]        entry_SYSCALL_64_after_hwframe+0x76/0x7e\n   [6.1903]\n            -\u003e #0 (\u0026delayed_node-\u003emutex){+.+.}-{3:3}:\n   [6.1913]        __lock_acquire+0x15e9/0x2820\n   [6.1920]        lock_acquire+0xc9/0x2d0\n   [6.1927]        __mutex_lock+0xcc/0x10a0\n   [6.1934]        __btrfs_release_delayed_node.part.0+0x39/0x2f0\n   [6.1944]        btrfs_evict_inode+0x20b/0x4b0\n   [6.1952]        evict+0x15a/0x2f0\n   [6.1958]        prune_icache_sb+0x91/0xd0\n   [6.1966]        super_cache_scan+0x150/0x1d0\n   [6.1974]        do_shrink_slab+0x155/0x6f0\n   [6.1981]        shrink_slab+0x48e/0x890\n   [6.1988]        shrink_one+0x11a/0x1f0\n   [6.1995]        shrink_node+0xbfd/0x1320\n   [6.1002]        balance_pgdat+0x67f/0xc60\n   [6.1321]        kswapd+0x1dc/0x3e0\n   [6.1643]        kthread+0xff/0x240\n   [6.1965]        ret_from_fork+0x223/0x280\n   [6.1287]        ret_from_fork_asm+0x1a/0x30\n   [6.1616]\n            other info that might help us debug this:\n\n   [6.1561] Chain exists of:\n              \u0026delayed_node-\u003emutex --\u003e btrfs-tree-00 --\u003e fs_reclaim\n\n   [6.1503]  Possible unsafe locking scenario:\n\n   [6.1110]        CPU0                    CPU1\n   [6.1411]        ----                    ----\n   [6.1707]   lock(fs_reclaim);\n   [6.1998]                                lock(btrfs-tree-00);\n   [6.1291]                                lock(fs_reclaim);\n   [6.1581]   lock(\u0026del\n---truncated---","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"btrfs: release path before initializing extent tree in btrfs_read_locked_inode()","id":"CVE-2026-23018","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"net: marvell: prestera: fix NULL dereference on devlink_alloc() failure","id":"CVE-2026-23019"},"packages":[],"prev":{"headline":"idpf: fix error handling in the init_task on load","id":"CVE-2026-23017"},"products":["Linux"],"published":"2026-01-31","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-23","vendors":["Linux"]},"summary":"A circular locking dependency in the btrfs filesystem can cause a deadlock during memory reclaim, leading to a system hang or denial of service.","url":"https://insights.sbomify.com/CVE-2026-23018/"}