FKIE_CVE-2026-64074

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap statmount_mnt_idmap() writes one mapping with seq_printf() and then manually advances seq->count to include the NUL separator. If seq_printf() overflows, seq_set_overflow() sets seq->count to seq->size. The manual seq->count++ changes this to seq->size + 1. seq_has_overflowed() then no longer detects the overflow. The corrupted count returns to statmount_string(), which later executes: seq->buf[seq->count++] = '\0'; This causes a 1-byte NULL out-of-bounds write on the dynamically allocated seq buffer. Fix this by checking for overflow immediately after seq_printf().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/93614949dc86f068e3c32c32cf1ee2a2323177a7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e37ea2c6f17f273813ea4e8e94c102591d598ce1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/mnt_idmapping.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e37ea2c6f17f273813ea4e8e94c102591d598ce1",
              "status": "affected",
              "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
              "versionType": "git"
            },
            {
              "lessThan": "93614949dc86f068e3c32c32cf1ee2a2323177a7",
              "status": "affected",
              "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
              "versionType": "git"
            },
            {
              "lessThan": "a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78",
              "status": "affected",
              "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/mnt_idmapping.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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\nfs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap\n\nstatmount_mnt_idmap() writes one mapping with seq_printf() and then\nmanually advances seq-\u003ecount to include the NUL separator.\n\nIf seq_printf() overflows, seq_set_overflow() sets seq-\u003ecount to\nseq-\u003esize. The manual seq-\u003ecount++ changes this to seq-\u003esize + 1.\nseq_has_overflowed() then no longer detects the overflow. The corrupted\ncount returns to statmount_string(), which later executes:\n\n    seq-\u003ebuf[seq-\u003ecount++] = \u0027\\0\u0027;\n\nThis causes a 1-byte NULL out-of-bounds write on the dynamically\nallocated seq buffer.\n\nFix this by checking for overflow immediately after seq_printf()."
    }
  ],
  "id": "CVE-2026-64074",
  "lastModified": "2026-07-20T15:17:07.050",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T16:17:48.010",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/93614949dc86f068e3c32c32cf1ee2a2323177a7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e37ea2c6f17f273813ea4e8e94c102591d598ce1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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