{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-40054 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-40054 is a high-severity use after free vulnerability in Linux, published on 28 Oct 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-2025-40054 and fix it if it is affected.\n\nWhat it is: CVE-2025-40054 is a high-severity use after free vulnerability in Linux, published on 28 Oct 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-2025-40054 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2025-40054/ (Markdown: https://insights.sbomify.com/CVE-2025-40054/index.md)","id":"CVE-2025-40054","markdown":"https://insights.sbomify.com/CVE-2025-40054/index.md","name":"CVE-2025-40054","record":{"aliases":["BELL-CVE-2025-40054","DEBIAN-CVE-2025-40054","GHSA-2xf6-75gh-3848","ROOT-OS-DEBIAN-11-CVE-2025-40054","ROOT-OS-DEBIAN-12-CVE-2025-40054","ROOT-OS-DEBIAN-13-CVE-2025-40054","ROOT-OS-UBUNTU-2204-CVE-2025-40054","ROOT-OS-UBUNTU-2404-CVE-2025-40054","UBUNTU-CVE-2025-40054"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free race condition in the Linux kernel's f2fs filesystem can cause a system crash during writeback operations.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix UAF issue in f2fs_merge_page_bio()\n\nAs JY reported in bugzilla [1],\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000000\npc : [0xffffffe51d249484] f2fs_is_cp_guaranteed+0x70/0x98\nlr : [0xffffffe51d24adbc] f2fs_merge_page_bio+0x520/0x6d4\nCPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P    B   W  OE      6.12.30-android16-5-maybe-dirty-4k #1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5\nTainted: [P]=PROPRIETARY_MODULE, [B]=BAD_PAGE, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\nWorkqueue: writeback wb_workfn (flush-254:49)\nCall trace:\n f2fs_is_cp_guaranteed+0x70/0x98\n f2fs_inplace_write_data+0x174/0x2f4\n f2fs_do_write_data_page+0x214/0x81c\n f2fs_write_single_data_page+0x28c/0x764\n f2fs_write_data_pages+0x78c/0xce4\n do_writepages+0xe8/0x2fc\n __writeback_single_inode+0x4c/0x4b4\n writeback_sb_inodes+0x314/0x540\n __writeback_inodes_wb+0xa4/0xf4\n wb_writeback+0x160/0x448\n wb_workfn+0x2f0/0x5dc\n process_scheduled_works+0x1c8/0x458\n worker_thread+0x334/0x3f0\n kthread+0x118/0x1ac\n ret_from_fork+0x10/0x20\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=220575\n\nThe panic was caused by UAF issue w/ below race condition:\n\nkworker\n- writepages\n - f2fs_write_cache_pages\n  - f2fs_write_single_data_page\n   - f2fs_do_write_data_page\n    - f2fs_inplace_write_data\n     - f2fs_merge_page_bio\n      - add_inu_page\n      : cache page #1 into bio \u0026 cache bio in\n        io-\u003ebio_list\n  - f2fs_write_single_data_page\n   - f2fs_do_write_data_page\n    - f2fs_inplace_write_data\n     - f2fs_merge_page_bio\n      - add_inu_page\n      : cache page #2 into bio which is linked\n        in io-\u003ebio_list\n\t\t\t\t\t\twrite\n\t\t\t\t\t\t- f2fs_write_begin\n\t\t\t\t\t\t: write page #1\n\t\t\t\t\t\t - f2fs_folio_wait_writeback\n\t\t\t\t\t\t  - f2fs_submit_merged_ipu_write\n\t\t\t\t\t\t   - f2fs_submit_write_bio\n\t\t\t\t\t\t   : submit bio which inclues page #1 and #2\n\n\t\t\t\t\t\tsoftware IRQ\n\t\t\t\t\t\t- f2fs_write_end_io\n\t\t\t\t\t\t - fscrypt_free_bounce_page\n\t\t\t\t\t\t : freed bounced page which belongs to page #2\n      - inc_page_count( , WB_DATA_TYPE(data_folio), false)\n      : data_folio points to fio-\u003eencrypted_page\n        the bounced page can be freed before\n        accessing it in f2fs_is_cp_guarantee()\n\nIt can reproduce w/ below testcase:\nRun below script in shell #1:\nfor ((i=1;i\u003e0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c \"pwrite 0 32k\" -c \"fdatasync\"\n\nRun below script in shell #2:\nfor ((i=1;i\u003e0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c \"pwrite 0 32k\" -c \"fdatasync\"\n\nSo, in f2fs_merge_page_bio(), let's avoid using fio-\u003eencrypted_page after\ncommit page into internal ipu cache.","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":"f2fs: fix UAF issue in f2fs_merge_page_bio()","id":"CVE-2025-40054","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":7,"next":{"headline":"ocfs2: fix double free in user_cluster_connect()","id":"CVE-2025-40055"},"packages":[],"prev":{"headline":"net: dlink: handle copy_thresh allocation failure","id":"CVE-2025-40053"},"products":["Linux"],"published":"2025-10-28","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-23","vendors":["Linux"]},"summary":"A use-after-free race condition in the Linux kernel's f2fs filesystem can cause a system crash during writeback operations.","url":"https://insights.sbomify.com/CVE-2025-40054/"}