writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-98538
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-18 16:17:05 UTC
Updated2026-10-18 16:17:05 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes cleanup_offline_cgwb() prepares at most WB_MAX_INODES_PER_ISW inodes per call and is called again until the dying wb is drained, but every call walks wb->b_attached and then wb->b_dirty_time from the same end. Inodes already prepared (they stay on the list with I_WB_SWITCH set until the switch worker runs) and inodes that cannot be switched (I_FREEING, I_WILL_FREE, !SB_ACTIVE, DAX, already on the target wb) stay where they are, so each pass rescans a growing run of them under wb->list_lock and a full drain is quadratic in the number of inodes on the list. With ~17M inodes attached to one dying cgwb we saw this end in soft lockups, with CPUs reported stuck for 21-48s. Walk both lists from the oldest end and move every scanned inode to the newest end, so the next pass starts where the previous one stopped and the drain becomes linear. b_attached is unordered, so nobody sees the reorder there. b_dirty_time is ordered by dirtied_when, but the oldest unscanned inode stays at the end move_expired_inodes() picks from, sync takes the whole list regardless of order, and prepared inodes leave the list as soon as the switch work runs and get a new dirtied_time_when on the new wb anyway, so the only inodes left out of order are the ones that can never switch (DAX), and only on the dying wb.

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 2d1da58c79b66646721a644c6eb4dd1f9c5c9327 git Not specified
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 c96b4d1628868e1195da1a896f79e06f350a3187 git Not specified
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 624dd0931162523d70f9db8c120b5ec6429a9b97 git Not specified
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 dd4b92067238771b604b59fdda8efed6d70ee823 git Not specified
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 9dac137bf77e0683778fb34c86e730c6129e8cb6 git Not specified
CNA Linux Linux affected c22d70a162d3cc177282c4487be4d54876ca55c8 f6988c90671e83db79df1b7b9d6fdb0e5947fd84 git Not specified
CNA Linux Linux affected 5.14 Not specified
CNA Linux Linux unaffected 5.14 semver Not specified
CNA Linux Linux unaffected 6.1.189 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.158 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.112 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.55 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.9 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/2d1da58c79b66646721a644c6eb4dd1f9c5c9327 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/dd4b92067238771b604b59fdda8efed6d70ee823 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/624dd0931162523d70f9db8c120b5ec6429a9b97 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/9dac137bf77e0683778fb34c86e730c6129e8cb6 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c96b4d1628868e1195da1a896f79e06f350a3187 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f6988c90671e83db79df1b7b9d6fdb0e5947fd84 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report