{"id":"CVE-2026-98538","revision":"2ddeb7babf4747fcbd48b096ab150758","records":[{"revision":"2ddeb7babf4747fcbd48b096ab150758","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98538","aliases":[],"title":"writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwriteback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes\n\ncleanup_offline_cgwb() prepares at most WB_MAX_INODES_PER_ISW inodes\nper call and is called again until the dying wb is drained, but every\ncall walks wb->b_attached and then wb->b_dirty_time from the same end.\nInodes already prepared (they stay on the list with I_WB_SWITCH set\nuntil the switch worker runs) and inodes that cannot be switched\n(I_FREEING, I_WILL_FREE, !SB_ACTIVE, DAX, already on the target wb)\nstay where they are, so each pass rescans a growing run of them under\nwb->list_lock and a full drain is quadratic in the number of inodes on\nthe list. With ~17M inodes attached to one dying cgwb we saw this end\nin soft lockups, with CPUs reported stuck for 21-48s.\n\nWalk both lists from the oldest end and move every scanned inode to\nthe newest end, so the next pass starts where the previous one stopped\nand the drain becomes linear. b_attached is unordered, so nobody sees\nthe reorder there. b_dirty_time is ordered by dirtied_when, but the\noldest unscanned inode stays at the end move_expired_inodes() picks\nfrom, sync takes the whole list regardless of order, and prepared\ninodes leave the list as soon as the switch work runs and get a new\ndirtied_time_when on the new wb anyway, so the only inodes left out of\norder are the ones that can never switch (DAX), and only on the dying\nwb.","state":0,"publishedAt":"2026-10-18T15:18:05.901+00:00","modifiedAt":"2026-10-19T09:21:21.678+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/fs-writeback.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"2d1da58c79b66646721a644c6eb4dd1f9c5c9327\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"c96b4d1628868e1195da1a896f79e06f350a3187\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"624dd0931162523d70f9db8c120b5ec6429a9b97\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"dd4b92067238771b604b59fdda8efed6d70ee823\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"9dac137bf77e0683778fb34c86e730c6129e8cb6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c22d70a162d3cc177282c4487be4d54876ca55c8\",\n                            \"lessThan\": \"f6988c90671e83db79df1b7b9d6fdb0e5947fd84\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/fs-writeback.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.14\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.14\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.55\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.9\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/2d1da58c79b66646721a644c6eb4dd1f9c5c9327","https://git.kernel.org/stable/c/c96b4d1628868e1195da1a896f79e06f350a3187","https://git.kernel.org/stable/c/624dd0931162523d70f9db8c120b5ec6429a9b97","https://git.kernel.org/stable/c/dd4b92067238771b604b59fdda8efed6d70ee823","https://git.kernel.org/stable/c/9dac137bf77e0683778fb34c86e730c6129e8cb6","https://git.kernel.org/stable/c/f6988c90671e83db79df1b7b9d6fdb0e5947fd84"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98538","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98538","identifiers":["CVE-2026-98538"]},"retained":false,"historicalAffected":[]}],"coverage":[]}