{"id":"CVE-2026-23234","summary":"f2fs: fix to avoid UAF in f2fs_write_end_io()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid UAF in f2fs_write_end_io()\n\nAs syzbot reported an use-after-free issue in f2fs_write_end_io().\n\nIt is caused by below race condition:\n\nloop device\t\t\t\tumount\n- worker_thread\n - loop_process_work\n  - do_req_filebacked\n   - lo_rw_aio\n    - lo_rw_aio_complete\n     - blk_mq_end_request\n      - blk_update_request\n       - f2fs_write_end_io\n        - dec_page_count\n        - folio_end_writeback\n\t\t\t\t\t- kill_f2fs_super\n\t\t\t\t\t - kill_block_super\n\t\t\t\t\t  - f2fs_put_super\n\t\t\t\t\t : free(sbi)\n       : get_pages(, F2FS_WB_CP_DATA)\n         accessed sbi which is freed\n\nIn kill_f2fs_super(), we will drop all page caches of f2fs inodes before\ncall free(sbi), it guarantee that all folios should end its writeback, so\nit should be safe to access sbi before last folio_end_writeback().\n\nLet's relocate ckpt thread wakeup flow before folio_end_writeback() to\nresolve this issue.","modified":"2026-04-02T13:12:16.096025Z","published":"2026-03-04T14:36:38.843Z","related":["openSUSE-SU-2026:10387-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23234.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0fb58aff0dafd6837cc91f4154f3ed6e020358fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f67ff1e15a8a4d0e4ffc6564ab20d03d7398fe9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/505e1c0530db6152cab3feef8e3e4da3d3e358c9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/995030be4ce6338c6ff814583c14166446a64008"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a42f99be8a16b32a0bb91bb6dda212a6ad61be5d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/acc2c97fc0005846e5cf11b5ba3189fef130c9b3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce2739e482bce8d2c014d76c4531c877f382aa54"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf4a9e1bc8129eb63fda5f8bdcd8d87f0bd76f42"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23234.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23234"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e234088758fca3a669ebb1a02d8bf7bf60f0e4ff"},{"fixed":"0fb58aff0dafd6837cc91f4154f3ed6e020358fa"},{"fixed":"2f67ff1e15a8a4d0e4ffc6564ab20d03d7398fe9"},{"fixed":"505e1c0530db6152cab3feef8e3e4da3d3e358c9"},{"fixed":"acc2c97fc0005846e5cf11b5ba3189fef130c9b3"},{"fixed":"cf4a9e1bc8129eb63fda5f8bdcd8d87f0bd76f42"},{"fixed":"995030be4ce6338c6ff814583c14166446a64008"},{"fixed":"a42f99be8a16b32a0bb91bb6dda212a6ad61be5d"},{"fixed":"ce2739e482bce8d2c014d76c4531c877f382aa54"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23234.json"}}],"schema_version":"1.7.5"}