CVE-2026-23234
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_write_end_io() As syzbot reported an use-after-free issue in…
Impact
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_write_end_io() As syzbot reported an use-after-free issue in f2fs_write_end_io(). It is caused by below race condition: loop device umount - worker_thread - loop_process_work - do_req_filebacked - lo_rw_aio - lo_rw_aio_complete - blk_mq_end_request - blk_update_request - f2fs_write_end_io - dec_page_count - folio_end_writeback - kill_f2fs_super - kill_block_super - f2fs_put_super : free(sbi) : get_pages(, F2FS_WB_CP_DATA) accessed sbi which is freed In kill_f2fs_super(), we will drop all page caches of f2fs inodes before call free(sbi), it guarantee that all folios should end its writeback, so it should be safe to access sbi before last folio_end_writeback(). Let's relocate ckpt thread wakeup flow before folio_end_writeback() to resolve this issue.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Linux | Linux Kernel | from 3.13 before 5.10.251 from 5.11 before 5.15.201 from 5.16 before 6.1.164 from 6.2 before 6.6.127 from 6.7 before 6.12.74 from 6.13 before 6.18.13 |
Weakness classification
References
- NVD record
- CVE.org record
- https://git.kernel.org/stable/c/0fb58aff0dafd6837cc91f4154f3ed6e020358fa
- https://git.kernel.org/stable/c/2f67ff1e15a8a4d0e4ffc6564ab20d03d7398fe9
- https://git.kernel.org/stable/c/505e1c0530db6152cab3feef8e3e4da3d3e358c9
- https://git.kernel.org/stable/c/995030be4ce6338c6ff814583c14166446a64008
- https://git.kernel.org/stable/c/a42f99be8a16b32a0bb91bb6dda212a6ad61be5d
- https://git.kernel.org/stable/c/acc2c97fc0005846e5cf11b5ba3189fef130c9b3
- https://git.kernel.org/stable/c/ce2739e482bce8d2c014d76c4531c877f382aa54
- https://git.kernel.org/stable/c/cf4a9e1bc8129eb63fda5f8bdcd8d87f0bd76f42