CVE-2026-68442

{
  "id": "CVE-2026-68442",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-12T00:17:44.477",
  "lastModified": "2026-10-19T22:17:19.330",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps\n\nWhen btrfs_drop_extent_map_range() splits an extent map, the new split\nmaps inherit the original map's flags through a local 'flags' variable.\nCommit f86f7a75e2fb (\"btrfs: use the flags of an extent map to identify\nthe compression type\") changed the EXTENT_FLAG_LOGGING clearing to\noperate on em->flags instead of that local 'flags' copy, so a split of\nan extent map that is currently being logged wrongly inherits\nEXTENT_FLAG_LOGGING.\n\nThe flag is then never cleared on the split, and when it is freed while\nstill on the inode's modified_extents list (for example by the extent\nmap shrinker) it trips the WARN_ON(!list_empty(&em->list)) in\nbtrfs_free_extent_map() and leads to a use-after-free.\n\nClear EXTENT_FLAG_LOGGING from the local 'flags' copy used for the\nsplits and only clear EXTENT_FLAG_PINNED from em->flags, restoring the\nbehaviour prior to f86f7a75e2fb."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/btrfs/extent_map.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9",
              "lessThan": "2a9246a424f45f33a1b8367052611ebe874868ad",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9",
              "lessThan": "9304713b70e7e1450e3a76e758836fe5391bfa95",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9",
              "lessThan": "0e465c63f103a5ce6849614d6bda048d70eebec8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9",
              "lessThan": "5eff4d5b17fa1950e80bfd1ba43dc0699e61a644",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/btrfs/extent_map.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.8",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.101",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.42",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:48:58.466646Z",
          "id": "CVE-2026-68442",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0e465c63f103a5ce6849614d6bda048d70eebec8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2a9246a424f45f33a1b8367052611ebe874868ad",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5eff4d5b17fa1950e80bfd1ba43dc0699e61a644",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9304713b70e7e1450e3a76e758836fe5391bfa95",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}