{"id":"CVE-2026-89558","title":"md/raid10: fix still_degraded being inverted in raid10_sync_request()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd/raid10: fix still_degraded being inverted in raid10_sync_request()\n\nCommit fe6a19d40ceb (\"md/md-bitmap: merge md_bitmap_start_sync() into\nbitmap_operations\") convert…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-480"],"vendor":"Linux","product":"Linux","affected":["Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4","Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 0efabe6229dc683dbf6eeebd0f9fddc7971ed420","Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 00449d752bee9c8787f42ea1bf533a9fb17f9b6b","Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 47f1441b281decde6954a2fa82b4131637d685ac","Linux 6.12"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:48:51.700Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89558","references":[{"url":"https://git.kernel.org/stable/c/9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4"},{"url":"https://git.kernel.org/stable/c/0efabe6229dc683dbf6eeebd0f9fddc7971ed420"},{"url":"https://git.kernel.org/stable/c/00449d752bee9c8787f42ea1bf533a9fb17f9b6b"},{"url":"https://git.kernel.org/stable/c/47f1441b281decde6954a2fa82b4131637d685ac"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89558.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89558"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532221"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89558"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89558"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89558.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00635,"epssPercentile":0.50214,"scores":{"cna":9.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.474Z","slug":"CVE-2026-89558","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmd/raid10: fix still_degraded being inverted in raid10_sync_request()\n\nCommit fe6a19d40ceb (\"md/md-bitmap: merge md_bitmap_start_sync() into\nbitmap_operations\") converted still_degraded from int to bool, but\ninverted the assignment in the loop that checks whether the array will\nstill be degraded after the current device is recovered:\n\"still_degraded = 1\" became \"still_degraded = false\".\n\nAs a result, recovering a device while another mirror is still missing\ncalls md_bitmap_start_sync() with degraded == false, which clears bitmap\nbits that the still-missing device needs.  When that device is re-added,\nits bitmap-based recovery finds the bits already cleared and skips every\nregion written while the array was degraded, so it is marked In_sync\nwhile holding stale data: silent corruption.\n\nReproducer (raid10 near=2, 4 disks, internal bitmap):\n - fail and remove one disk of each mirror pair\n - write to the degraded array\n - re-add both disks and let recovery finish\n - \"check\" reports mismatch_cnt=262272 after 256 MiB of degraded\n   writes and file contents differ; the second disk's \"recovery\"\n   completes in milliseconds because everything is skipped\n\nThe same conversion in raid1 got it right (still_degraded = true).\nRestore the correct value.\n\n## Affected\n\n- `Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4`\n- `Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 0efabe6229dc683dbf6eeebd0f9fddc7971ed420`\n- `Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 00449d752bee9c8787f42ea1bf533a9fb17f9b6b`\n- `Linux >= fe6a19d40ceb44281905485f56dda715e3214e0e < 47f1441b281decde6954a2fa82b4131637d685ac`\n- `Linux 6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89558.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":224711,"id":"CVE-2026-89558","ts":1792401486879,"field":"cvss","old":"7","new":"9.8"},{"seq":224710,"id":"CVE-2026-89558","ts":1792401486879,"field":"severity","old":"high","new":"critical"},{"seq":208101,"id":"CVE-2026-89558","ts":1789922708806,"field":"cvss","old":"4.4","new":"7"},{"seq":208100,"id":"CVE-2026-89558","ts":1789922708806,"field":"severity","old":"medium","new":"high"},{"seq":202883,"id":"CVE-2026-89558","ts":1789403732798,"field":"cvss","old":"9.8","new":"4.4"},{"seq":202882,"id":"CVE-2026-89558","ts":1789403732798,"field":"severity","old":"critical","new":"medium"},{"seq":197926,"id":"CVE-2026-89558","ts":1789384320981,"field":"cvss","old":"4.4","new":"9.8"},{"seq":197925,"id":"CVE-2026-89558","ts":1789384320981,"field":"severity","old":"medium","new":"critical"},{"seq":183477,"id":"CVE-2026-89558","ts":1789356675527,"field":"cvss","old":"9.8","new":"4.4"},{"seq":183476,"id":"CVE-2026-89558","ts":1789356675527,"field":"severity","old":"critical","new":"medium"},{"seq":153368,"id":"CVE-2026-89558","ts":1789285350235,"field":"cvss","old":null,"new":"9.8"},{"seq":153367,"id":"CVE-2026-89558","ts":1789285350235,"field":"severity","old":"none","new":"critical"},{"seq":147528,"id":"CVE-2026-89558","ts":1789270211262,"field":"cvss","old":null,"new":"4.4"},{"seq":147527,"id":"CVE-2026-89558","ts":1789270211262,"field":"severity","old":"none","new":"medium"},{"seq":109280,"id":"CVE-2026-89558","ts":1789183731259,"field":"cvss","old":null,"new":"4.4"},{"seq":109279,"id":"CVE-2026-89558","ts":1789183731259,"field":"severity","old":"none","new":"medium"}]}