CVE-2026-98538

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98538", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.356Z", "datePublished": "2026-10-18T15:18:05.901Z", "dateUpdated": "2026-10-19T09:21:21.678Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:21:21.678Z"}, "descriptions": [{"lang": "en", "value": "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fs-writeback.c"], "versions": [{"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "2d1da58c79b66646721a644c6eb4dd1f9c5c9327", "status": "affected", "versionType": "git"}, {"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "c96b4d1628868e1195da1a896f79e06f350a3187", "status": "affected", "versionType": "git"}, {"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "624dd0931162523d70f9db8c120b5ec6429a9b97", "status": "affected", "versionType": "git"}, {"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "dd4b92067238771b604b59fdda8efed6d70ee823", "status": "affected", "versionType": "git"}, {"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "9dac137bf77e0683778fb34c86e730c6129e8cb6", "status": "affected", "versionType": "git"}, {"version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "lessThan": "f6988c90671e83db79df1b7b9d6fdb0e5947fd84", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fs-writeback.c"], "versions": [{"version": "5.14", "status": "affected"}, {"version": "0", "lessThan": "5.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.55", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.9", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.12.112"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.18.55"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.2.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2d1da58c79b66646721a644c6eb4dd1f9c5c9327"}, {"url": "https://git.kernel.org/stable/c/c96b4d1628868e1195da1a896f79e06f350a3187"}, {"url": "https://git.kernel.org/stable/c/624dd0931162523d70f9db8c120b5ec6429a9b97"}, {"url": "https://git.kernel.org/stable/c/dd4b92067238771b604b59fdda8efed6d70ee823"}, {"url": "https://git.kernel.org/stable/c/9dac137bf77e0683778fb34c86e730c6129e8cb6"}, {"url": "https://git.kernel.org/stable/c/f6988c90671e83db79df1b7b9d6fdb0e5947fd84"}], "title": "writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/fs-writeback.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2d1da58c79b66646721a644c6eb4dd1f9c5c9327", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}, {"lessThan": "c96b4d1628868e1195da1a896f79e06f350a3187", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}, {"lessThan": "624dd0931162523d70f9db8c120b5ec6429a9b97", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}, {"lessThan": "dd4b92067238771b604b59fdda8efed6d70ee823", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}, {"lessThan": "9dac137bf77e0683778fb34c86e730c6129e8cb6", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}, {"lessThan": "f6988c90671e83db79df1b7b9d6fdb0e5947fd84", "status": "affected", "version": "c22d70a162d3cc177282c4487be4d54876ca55c8", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/fs-writeback.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.14"}, {"lessThan": "5.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.189", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.112", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.55", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-98538", "lastModified": "2026-10-19T10:19:09.527", "metrics": {}, "published": "2026-10-18T16:17:05.613", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2d1da58c79b66646721a644c6eb4dd1f9c5c9327"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/624dd0931162523d70f9db8c120b5ec6429a9b97"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9dac137bf77e0683778fb34c86e730c6129e8cb6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c96b4d1628868e1195da1a896f79e06f350a3187"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dd4b92067238771b604b59fdda8efed6d70ee823"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f6988c90671e83db79df1b7b9d6fdb0e5947fd84"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes", "id": "2554996", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2554996"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-1050", "details": ["A flaw was found in the Linux kernel's writeback subsystem. This flaw allows a local user to cause a Denial of Service (DoS) by triggering prolonged processor stalls. When the kernel cleans up offline control group writeback structures with a large number of cached files, it repeatedly rescans already processed entries while holding an internal lock. This inefficient traversal can trigger a soft lockup where processors become stuck, rendering the system unresponsive."], "name": "CVE-2026-98538", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-98538\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-98538\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98538.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,2d1da58c79b66646721a644c6eb4dd1f9c5c9327)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,c96b4d1628868e1195da1a896f79e06f350a3187)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,624dd0931162523d70f9db8c120b5ec6429a9b97)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,dd4b92067238771b604b59fdda8efed6d70ee823)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,9dac137bf77e0683778fb34c86e730c6129e8cb6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c22d70a162d3cc177282c4487be4d54876ca55c8,f6988c90671e83db79df1b7b9d6fdb0e5947fd84)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.14"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.14)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.189,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.158,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.112,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.55,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.9,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc5,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-10-19T01:00:10.576808+00:00", "updated": "2026-10-20T16:30:06.793816+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}