CVE-2026-23267 | f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by concurrent atomic commit and checkpoint writes

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by concurrent atomic commit and checkpoint writes During SPO tests, when mounting F2FS, an -EINVAL error was returned from f2fs_recover_inode_page. The issue occurred under the following scenario Thread A Thread B f2fs_ioc_commit_atomic_write - f2fs_do_sync_file // atomic = true - f2fs_fsync_node_pages : last_folio = inode folio : schedule before folio_lock(last_folio) f2fs_write_checkpoint - block_operations// writeback last_folio - schedule before f2fs_flush_nat_entries : set_fsync_mark(last_folio, 1) : set_dentry_mark(last_folio, 1) : folio_mark_dirty(last_folio) - __write_node_folio(last_folio) : f2fs_down_read(&sbi->node_write)//block - f2fs_flush_nat_entries : {struct nat_entry}->flag |= BIT(IS_CHECKPOINTED) - unblock_operations : f2fs_up_write(&sbi->node_write) f2fs_write_checkpoint//return : f2fs_do_write_node_page() f2fs_ioc_commit_atomic_write//return SPO Thread A calls f2fs_need_dentry_mark(sbi, ino), and the last_folio has already been written once. However, the {struct nat_entry}->flag did not have the IS_CHECKPOINTED set, causing set_dentry_mark(last_folio, 1) and write last_folio again after Thread B finishes f2fs_write_checkpoint. After SPO and reboot, it was detected that {struct node_info}->blk_addr was not NULL_ADDR because Thread B successfully write the checkpoint. This issue only occurs in atomic write scenarios. For regular file fsync operations, the folio must be dirty. If block_operations->f2fs_sync_node_pages successfully submit the folio write, this path will not be executed. Otherwise, the f2fs_write_checkpoint will need to wait for the folio write submission to complete, as sbi->nr_pages[F2FS_DIRTY_NODES] > 0. Therefore, the situation where f2fs_need_dentry_mark checks that the {struct nat_entry}->flag /wo the IS_CHECKPOINTED flag, but the folio write has already been submitted, will not occur. Therefore, for atomic file fsync, sbi->node_write should be acquired through __write_node_folio to ensure that the IS_CHECKPOINTED flag correctly indicates that the checkpoint write has been completed.

Published: 2026-03-18 Last update: 2026-05-29 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2026-23267 is rated Low Risk (24.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23267

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-19 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23267

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-23267

GitHub Security Advisory for CVE-2026-23267

GHSA-9m9w-6gjg-9m6r · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: f2fs: fix IS_CHECKPOINTED...

OS Trackers for CVE-2026-23267

vendor priority summary link
debian not yet assigned CVE-2026-23267 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-23267
redhat https://access.redhat.com/security/cve/CVE-2026-23267
suse medium CVE-2026-23267 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 236 product×package rows across 41 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (41 product lines)): Known Not Affected 236. https://www.suse.com/security/cve/CVE-2026-23267/
ubuntu medium CVE-2026-23267 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 170, needed 124, released 83, not-affected 8. https://ubuntu.com/security/CVE-2026-23267

Affected software / configurations for CVE-2026-23267

Vendor Product Version Raw CPE
linux linux_kernel >= 4.7, < 6.1.164 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.127 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.74 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.18.13 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19, < 6.19.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2026-23267

cvelogic Threat Intelligence