CVE-2026-90401 (GCVE-0-2026-90401)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:09 – Updated: 2026-10-19 09:03
VLAI
Title
md: remove REQ_NOWAIT support from raid1/10/456
Summary
In the Linux kernel, the following vulnerability has been resolved: md: remove REQ_NOWAIT support from raid1/10/456 REQ_NOWAIT support in md personalities that can block internally is fundamentally incomplete. While reads can avoid some blocking paths, write requests can still encounter cases where one mirror succeeds while another returns -EAGAIN. At that point md cannot distinguish queue pressure from a real device failure, so it can neither record a bad block nor safely retry the write without REQ_NOWAIT, leaving mirrors with divergent data. Rather than continue advertising REQ_NOWAIT support for personalities that cannot implement it correctly, remove it from raid1, raid10 and raid456. Keep REQ_NOWAIT for linear and raid0, which only remap bios to their underlying devices; stacked limits will still clear the feature if any component device lacks REQ_NOWAIT support.
Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6641 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: f51d46d0e7cb5b8494aa534d276a9d8915a2443d , < ffcc9ea4e4d121c78aef6654a1577aa7d120774d (git)
Affected: f51d46d0e7cb5b8494aa534d276a9d8915a2443d , < 9bb9504e2d8f3d22ef12d51c333dd499f402dc8f (git)
Affected: f51d46d0e7cb5b8494aa534d276a9d8915a2443d , < 3fe5b7c9fb72ccc29bfd0f955b124892af7e3674 (git)
Affected: 39db562b3fedb93978a7e42dd216b306740959f8 (git)
Affected: 5.15.111 , < 5.16 (semver)
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Linux Linux Affected: 5.17
Unaffected: 0 , < 5.17 (semver)
Unaffected: 6.18.57 , ≤ 6.18.* (semver)
Unaffected: 7.2.6 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
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      "affected": [
        {
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          "product": "Linux",
          "programFiles": [
            "drivers/md/md-bitmap.c",
            "drivers/md/md-bitmap.h",
            "drivers/md/md-linear.c",
            "drivers/md/md-llbitmap.c",
            "drivers/md/md.c",
            "drivers/md/raid0.c",
            "drivers/md/raid1-10.c",
            "drivers/md/raid1.c",
            "drivers/md/raid10.c",
            "drivers/md/raid5.c"
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          "programFiles": [
            "drivers/md/md-bitmap.c",
            "drivers/md/md-bitmap.h",
            "drivers/md/md-linear.c",
            "drivers/md/md-llbitmap.c",
            "drivers/md/md.c",
            "drivers/md/raid0.c",
            "drivers/md/raid1-10.c",
            "drivers/md/raid1.c",
            "drivers/md/raid10.c",
            "drivers/md/raid5.c"
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          "versions": [
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              "version": "6.18.57",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
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                  "versionStartIncluding": "5.17",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd: remove REQ_NOWAIT support from raid1/10/456\n\nREQ_NOWAIT support in md personalities that can block internally is\nfundamentally incomplete. While reads can avoid some blocking paths,\nwrite requests can still encounter cases where one mirror succeeds while\nanother returns -EAGAIN. At that point md cannot distinguish queue\npressure from a real device failure, so it can neither record a bad\nblock nor safely retry the write without REQ_NOWAIT, leaving mirrors\nwith divergent data.\n\nRather than continue advertising REQ_NOWAIT support for personalities\nthat cannot implement it correctly, remove it from raid1, raid10 and\nraid456. Keep REQ_NOWAIT for linear and raid0, which only remap bios to\ntheir underlying devices; stacked limits will still clear the feature if\nany component device lacks REQ_NOWAIT support."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The REQ_NOWAIT bit that drives the bug is set in blkdev_direct_IO() from IOCB_NOWAIT (pwritev2 RWF_NOWAIT or io_uring io_write() with O_DIRECT) on the md gendisk, then md_submit_bio()-\u003eraid1_write_request()/raid10_write_request(). nfsd, ksmbd, nvmet_bdev_execute_rw(), and iSCSI iblock submit ordinary READ/WRITE bios without REQ_NOWAIT, so no protocol message carries the flag.\nAC:L - md_init_stacking_limits() advertised BLK_FEAT_NOWAIT, so member clones kept REQ_NOWAIT and raid1_should_handle_error() ignored their failures. The attacker issues concurrent O_DIRECT nowait writes via io_uring/pwritev2 to fill one member\u0027s request queue until it returns BLK_STS_AGAIN while the other mirror completes; no uninfluenced race is required.\nPR:L - blkdev_direct_IO() performs no capable() check. Any process that can open the md node or a stacked dm LV (disk group, container CSI block volume, or a delegated /dev/mdX) can issue RWF_NOWAIT O_DIRECT I/O; init-namespace root is not required.\nUI:N - The attacker opens the md block device themselves and issues pwritev2(RWF_NOWAIT) or io_uring io_write(); no separate victim must mount a filesystem, attach media, or confirm an action.\nS:U - Divergent raid1/raid10 mirrors and skipped WriteErrorSeen/bad-block recording remain inside the host md array. The bug does not escape a VM, bypass an IOMMU, or cross another security authority.\nC:N - raid1_end_write_request() ignore_error only skips WriteErrorSeen and R1BIO_WriteError; it does not read other tenants\u0027 data or kernel memory. A failed nowait read forced uptodate in raid1_end_read_request() completes into the attacker\u0027s own O_DIRECT buffers.\nI:H - When one raid1/raid10 clone succeeds and another returns BLK_STS_AGAIN, raid1_should_handle_error() sets ignore_error, raid1_end_write_request() still sets R1BIO_Uptodate, and raid_end_bio_io() reports success while mirrors hold different data and real member failures are not recorded as bad blocks.\nA:H - raid5 make_discard_request() returned without bio_endio() on REQ_NOWAIT, hanging the discard bio. Ignored member failures also leave a disk In_sync after a nowait EAGAIN, so a later loss of the up-to-date mirror makes diverged sectors unrecoverable and can take the array/filesystem offline."
            }
          ]
        }
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
        {
          "url": "https://git.kernel.org/stable/c/3fe5b7c9fb72ccc29bfd0f955b124892af7e3674"
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      ],
      "title": "md: remove REQ_NOWAIT support from raid1/10/456",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90401",
    "datePublished": "2026-09-17T16:09:31.556Z",
    "dateReserved": "2026-09-11T19:38:34.811Z",
    "dateUpdated": "2026-10-19T09:03:05.286Z",
    "state": "PUBLISHED"
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      "date": "2026-11-13",
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                  "drivers/md/md.c",
                  "drivers/md/raid0.c",
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                  "drivers/md/md-linear.c",
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                  "drivers/md/md.c",
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        "descriptions": [
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd: remove REQ_NOWAIT support from raid1/10/456\n\nREQ_NOWAIT support in md personalities that can block internally is\nfundamentally incomplete. While reads can avoid some blocking paths,\nwrite requests can still encounter cases where one mirror succeeds while\nanother returns -EAGAIN. At that point md cannot distinguish queue\npressure from a real device failure, so it can neither record a bad\nblock nor safely retry the write without REQ_NOWAIT, leaving mirrors\nwith divergent data.\n\nRather than continue advertising REQ_NOWAIT support for personalities\nthat cannot implement it correctly, remove it from raid1, raid10 and\nraid456. Keep REQ_NOWAIT for linear and raid0, which only remap bios to\ntheir underlying devices; stacked limits will still clear the feature if\nany component device lacks REQ_NOWAIT support."
          }
        ],
        "id": "CVE-2026-90401",
        "lastModified": "2026-10-19T09:19:34.223",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.1,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
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              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
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        "published": "2026-09-17T17:17:39.877",
        "references": [
          {
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        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-11-06T01:42:51+00:00",
      "cve": "CVE-2026-90401",
      "id": "CVE-2026-90401",
      "initial_release_date": "2026-09-17T00:00:00+00:00",
      "product_status:known_affected": "174",
      "product_status:known_not_affected": "29",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: md: remove REQ_NOWAIT support from raid1/10/456",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90401.json",
      "version": "3"
    }
  }
}



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