CVE-2026-43065

Estado: AnalizadaMedia (5.5)—

In the Linux kernel, the following vulnerability has been resolved:

ext4: always drain queued discard work in ext4_mb_release()

While reviewing recent ext4 patch[1], Sashiko raised the following concern[2]:

> If the filesystem is initially mounted with the discard option, > deleting files will populate sbi->s_discard_list and queue > s_discard_work. If it is then remounted with nodiscard, the > EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is > neither cancelled nor flushed.

[1] https://lore.kernel.org/r/20260319094545.19291-1-qiang.zhang@linux.dev/ [2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev

Leer descripción completaMostrar menos

The concern was valid, but it had nothing to do with the patch[1]. One of the problems with Sashiko in its current (early) form is that it will detect pre-existing issues and report it as a problem with the patch that it is reviewing.

In practice, it would be hard to hit deliberately (unless you are a malicious syzkaller fuzzer), since it would involve mounting the file system with -o discard, and then deleting a large number of files, remounting the file system with -o nodiscard, and then immediately unmounting the file system before the queued discard work has a change to drain on its own.

Fix it because it's a real bug, and to avoid Sashiko from raising this concern when analyzing future patches to mballoc.c.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 5.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.16%
Percentil entre todas las CVEs puntuadas: 5
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-43065",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "e96c2354b170aaa53300c8e8fd59e41b133160f7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "c360e9d0def4f4ae03254a67c683103908555b75",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "1c82f863f090ab899085bdfade073313384b514b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "9b4d9dda6a71ad3425c8109d27c4c6bfb9da97b8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "812b6a7cd3e7f3a3e8a24db85bc6313c26cb1098",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "b4737e26d4688b8aea88ad6ea4dbfeb6e78b0327",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55cdd0af2bc5ffc92a2deb745627755aecd5db33",
              "lessThan": "9ee29d20aab228adfb02ca93f87fb53c56c2f3af",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/ext4/mballoc.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.203",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.168",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.131",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.80",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19.11",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ext4/mballoc.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-05-05T16:16:15.683",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1c82f863f090ab899085bdfade073313384b514b",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/812b6a7cd3e7f3a3e8a24db85bc6313c26cb1098",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9b4d9dda6a71ad3425c8109d27c4c6bfb9da97b8",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9ee29d20aab228adfb02ca93f87fb53c56c2f3af",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b4737e26d4688b8aea88ad6ea4dbfeb6e78b0327",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c360e9d0def4f4ae03254a67c683103908555b75",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e96c2354b170aaa53300c8e8fd59e41b133160f7",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: always drain queued discard work in ext4_mb_release()\n\nWhile reviewing recent ext4 patch[1], Sashiko raised the following\nconcern[2]:\n\n> If the filesystem is initially mounted with the discard option,\n> deleting files will populate sbi->s_discard_list and queue\n> s_discard_work. If it is then remounted with nodiscard, the\n> EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is\n> neither cancelled nor flushed.\n\n[1] https://lore.kernel.org/r/20260319094545.19291-1-qiang.zhang@linux.dev/\n[2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev\n\nThe concern was valid, but it had nothing to do with the patch[1].\nOne of the problems with Sashiko in its current (early) form is that\nit will detect pre-existing issues and report it as a problem with the\npatch that it is reviewing.\n\nIn practice, it would be hard to hit deliberately (unless you are a\nmalicious syzkaller fuzzer), since it would involve mounting the file\nsystem with -o discard, and then deleting a large number of files,\nremounting the file system with -o nodiscard, and then immediately\nunmounting the file system before the queued discard work has a change\nto drain on its own.\n\nFix it because it's a real bug, and to avoid Sashiko from raising this\nconcern when analyzing future patches to mballoc.c."
    }
  ],
  "lastModified": "2026-06-17T10:48:52.057",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "85C0DA29-FD98-4182-B0A1-624E28976709",
              "versionEndExcluding": "5.15.203",
              "versionStartIncluding": "5.15"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E2DDDCA1-6DAB-4018-B920-8F045DDD8D3B",
              "versionEndExcluding": "6.1.168",
              "versionStartIncluding": "5.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CE6ED4D4-0046-4573-BFA9-D64143B6A89F",
              "versionEndExcluding": "6.6.131",
              "versionStartIncluding": "6.2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "97EB19EC-A11E-49C6-9D2F-6F6EC6CB98B6",
              "versionEndExcluding": "6.12.80",
              "versionStartIncluding": "6.7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE",
              "versionEndExcluding": "6.18.21",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7",
              "versionEndExcluding": "6.19.11",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}