CVE-2026-23234

Advisory lineage Upstream: 0 Downstream: 9
Analyzed
Published: 04 Mar 2026, 14:36
Last modified:11 May 2026, 22:02

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.02% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

04 Mar 2026, 14:36
Published
Vulnerability first disclosed
11 May 2026, 22:02
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.02%• Percentile: 6%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < 0fb58aff0dafd6837cc91f4154f3ed6e020358fa | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < 2f67ff1e15a8a4d0e4ffc6564ab20d03d7398fe9 | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < 505e1c0530db6152cab3feef8e3e4da3d3e358c9 | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < acc2c97fc0005846e5cf11b5ba3189fef130c9b3 | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < cf4a9e1bc8129eb63fda5f8bdcd8d87f0bd76f42 | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < 995030be4ce6338c6ff814583c14166446a64008 | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < a42f99be8a16b32a0bb91bb6dda212a6ad61be5d | ≥ e234088758fca3a669ebb1a02d8bf7bf60f0e4ff, < ce2739e482bce8d2c014d76c4531c877f382aa54 | 3.13

  • linux•linux_kernel

    ≥ 3.13, < 5.10.251 | ≥ 5.11, < 5.15.201 | ≥ 5.16, < 6.1.164 | ≥ 6.2, < 6.6.127 | ≥ 6.7, < 6.12.74 | ≥ 6.13, < 6.18.13 | ≥ 6.19, < 6.19.3

References (8)