{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21722 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21722 is a high-severity use after free vulnerability in Linux kernel, published on 27 Feb 2025. 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-2025-21722 and fix it if it is affected.\n\nWhat it is: CVE-2025-21722 is a high-severity use after free vulnerability in Linux kernel, published on 27 Feb 2025. 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-2025-21722 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-2025-21722/ (Markdown: https://insights.sbomify.com/CVE-2025-21722/index.md)","id":"CVE-2025-21722","markdown":"https://insights.sbomify.com/CVE-2025-21722/index.md","name":"CVE-2025-21722","record":{"aliases":["BELL-CVE-2025-21722","DEBIAN-CVE-2025-21722","GHSA-6g66-96c8-x7cw","ROOT-OS-UBUNTU-2404-CVE-2025-21722","UBUNTU-CVE-2025-21722"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel nilfs2","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the nilfs2 filesystem allows attackers to cause denial of service or potentially execute code via corrupted filesystem states.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: do not force clear folio if buffer is referenced\n\nPatch series \"nilfs2: protect busy buffer heads from being force-cleared\".\n\nThis series fixes the buffer head state inconsistency issues reported by\nsyzbot that occurs when the filesystem is corrupted and falls back to\nread-only, and the associated buffer head use-after-free issue.\n\nThis patch (of 2):\n\nSyzbot has reported that after nilfs2 detects filesystem corruption and\nfalls back to read-only, inconsistencies in the buffer state may occur.\n\nOne of the inconsistencies is that when nilfs2 calls mark_buffer_dirty()\nto set a data or metadata buffer as dirty, but it detects that the buffer\nis not in the uptodate state:\n\n WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520\n  fs/buffer.c:1177\n ...\n Call Trace:\n  \u003cTASK\u003e\n  nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598\n  nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73\n  nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344\n  nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218\n  vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257\n  do_mkdirat+0x264/0x3a0 fs/namei.c:4280\n  __do_sys_mkdirat fs/namei.c:4295 [inline]\n  __se_sys_mkdirat fs/namei.c:4293 [inline]\n  __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293\n  do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe other is when nilfs_btree_propagate(), which propagates the dirty\nstate to the ancestor nodes of a b-tree that point to a dirty buffer,\ndetects that the origin buffer is not dirty, even though it should be:\n\n WARNING: CPU: 0 PID: 5245 at fs/nilfs2/btree.c:2089\n  nilfs_btree_propagate+0xc79/0xdf0 fs/nilfs2/btree.c:2089\n ...\n Call Trace:\n  \u003cTASK\u003e\n  nilfs_bmap_propagate+0x75/0x120 fs/nilfs2/bmap.c:345\n  nilfs_collect_file_data+0x4d/0xd0 fs/nilfs2/segment.c:587\n  nilfs_segctor_apply_buffers+0x184/0x340 fs/nilfs2/segment.c:1006\n  nilfs_segctor_scan_file+0x28c/0xa50 fs/nilfs2/segment.c:1045\n  nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1216 [inline]\n  nilfs_segctor_collect fs/nilfs2/segment.c:1540 [inline]\n  nilfs_segctor_do_construct+0x1c28/0x6b90 fs/nilfs2/segment.c:2115\n  nilfs_segctor_construct+0x181/0x6b0 fs/nilfs2/segment.c:2479\n  nilfs_segctor_thread_construct fs/nilfs2/segment.c:2587 [inline]\n  nilfs_segctor_thread+0x69e/0xe80 fs/nilfs2/segment.c:2701\n  kthread+0x2f0/0x390 kernel/kthread.c:389\n  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n  \u003c/TASK\u003e\n\nBoth of these issues are caused by the callbacks that handle the\npage/folio write requests, forcibly clear various states, including the\nworking state of the buffers they hold, at unexpected times when they\ndetect read-only fallback.\n\nFix these issues by checking if the buffer is referenced before clearing\nthe page/folio state, and skipping the clear if it is.","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":"nilfs2: do not force clear folio if buffer is referenced","id":"CVE-2025-21722","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":8,"next":{"headline":"scsi: mpi3mr: Fix possible crash when setting up bsg fails","id":"CVE-2025-21723"},"packages":[],"prev":{"headline":"nilfs2: handle errors that nilfs_prepare_chunk() may return","id":"CVE-2025-21721"},"products":["Linux"],"published":"2025-02-27","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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-21","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the nilfs2 filesystem allows attackers to cause denial of service or potentially execute code via corrupted filesystem states.","url":"https://insights.sbomify.com/CVE-2025-21722/"}