CVE-2026-64267 (GCVE-0-2026-64267)
Vulnerability from cvelistv5
Published
2026-07-25 08:49
Modified
2026-08-17 04:52
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.
References
Impacted products
Vendor Product Version
Linux Linux Version: 3f29d59e92a96d843c2ff10ebfed92ac26878658
Version: 3f29d59e92a96d843c2ff10ebfed92ac26878658
Version: 3f29d59e92a96d843c2ff10ebfed92ac26878658
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev.c",
            "fs/fuse/notify.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6e2d84fdeac05bfd858e84a76353fdb84f23a43e",
              "status": "affected",
              "version": "3f29d59e92a96d843c2ff10ebfed92ac26878658",
              "versionType": "git"
            },
            {
              "lessThan": "c78c4b242299bc581e4987e5c2786c6f4760c516",
              "status": "affected",
              "version": "3f29d59e92a96d843c2ff10ebfed92ac26878658",
              "versionType": "git"
            },
            {
              "lessThan": "54243797cedf55447b4c5d560e8cd709900061ae",
              "status": "affected",
              "version": "3f29d59e92a96d843c2ff10ebfed92ac26878658",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev.c",
            "fs/fuse/notify.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "lessThan": "6.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: avoid 32-bit prune notification count wrap\n\nFUSE_NOTIFY_PRUNE validates the nodeid payload length with:\n\n    size - sizeof(outarg) != outarg.count * sizeof(u64)\n\nOn 32-bit kernels, size_t is also 32 bits, so the daemon-controlled\ncount multiplication can wrap.  A prune notification with count\n0x20000000 and no nodeid payload passes the check, enters the copy\nloop, and asks the device copy path to read nodeids that are not\npresent in the userspace write buffer.  In QEMU this reaches the\nfuse_copy_fill() BUG_ON(!err) path.\n\nValidate the payload length with array_size() instead.  That accepts\nexactly the same valid messages, but avoids wrapping arithmetic before\nthe copy loop consumes the count."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:52:21.187Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6e2d84fdeac05bfd858e84a76353fdb84f23a43e"
        },
        {
          "url": "https://git.kernel.org/stable/c/c78c4b242299bc581e4987e5c2786c6f4760c516"
        },
        {
          "url": "https://git.kernel.org/stable/c/54243797cedf55447b4c5d560e8cd709900061ae"
        }
      ],
      "title": "fuse: avoid 32-bit prune notification count wrap",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64267",
    "datePublished": "2026-07-25T08:49:15.720Z",
    "dateReserved": "2026-07-19T15:36:31.775Z",
    "dateUpdated": "2026-08-17T04:52:21.187Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.