Vulnerability-Lookup

CVE-2026-64264 (GCVE-0-2026-64264)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-25 08:49

Title

fuse-uring: fix EFAULT clobber in fuse_uring_commit

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix EFAULT clobber in fuse_uring_commit copy_from_user() returns the number of bytes not copied as an unsigned residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit stores that residual in ssize_t err, sets req->out.h.error to -EFAULT, then jumps to out: with err still holding the positive residual. err = copy_from_user(&req->out.h, &ent->headers->in_out, sizeof(req->out.h)); if (err) { req->out.h.error = -EFAULT; goto out; /* err is the positive residual */ } ... out: fuse_uring_req_end(ent, req, err); fuse_uring_req_end() then runs if (error) req->out.h.error = error; which overwrites the just-assigned -EFAULT with the positive residual. FUSE callers such as fuse_simple_request() test err < 0 to detect failure, so the positive value is interpreted as success and the caller proceeds with an uninitialised or partial req->out.args. Fix by assigning err = -EFAULT in the failure branch before jumping to out, so fuse_uring_req_end() receives a negative errno and sets req->out.h.error to -EFAULT.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/0483fffdeeb363f32…
https://git.kernel.org/stable/c/fe604c08d874648a6…
https://git.kernel.org/stable/c/3a0a8bc51a13951c5…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < 0483fffdeeb363f320e6bf5fc0f0306007507306 (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < fe604c08d874648a69187f6380e5c7858627dc04 (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < 3a0a8bc51a13951c5141262bf770eeea3e0b6228 (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0483fffdeeb363f320e6bf5fc0f0306007507306",
              "status": "affected",
              "version": "c090c8abae4b6b77a1bee116aa6c385456ebef96",
              "versionType": "git"
            },
            {
              "lessThan": "fe604c08d874648a69187f6380e5c7858627dc04",
              "status": "affected",
              "version": "c090c8abae4b6b77a1bee116aa6c385456ebef96",
              "versionType": "git"
            },
            {
              "lessThan": "3a0a8bc51a13951c5141262bf770eeea3e0b6228",
              "status": "affected",
              "version": "c090c8abae4b6b77a1bee116aa6c385456ebef96",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "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-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc1",
                  "versionStartIncluding": "6.14",
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                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix EFAULT clobber in fuse_uring_commit\n\ncopy_from_user() returns the number of bytes not copied as an unsigned\nresidual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit\nstores that residual in ssize_t err, sets req-\u003eout.h.error to -EFAULT,\nthen jumps to out: with err still holding the positive residual.\n\n    err = copy_from_user(\u0026req-\u003eout.h, \u0026ent-\u003eheaders-\u003ein_out,\n                         sizeof(req-\u003eout.h));\n    if (err) {\n        req-\u003eout.h.error = -EFAULT;\n        goto out;          /* err is the positive residual */\n    }\n    ...\n    out:\n        fuse_uring_req_end(ent, req, err);\n\nfuse_uring_req_end() then runs\n\n    if (error)\n        req-\u003eout.h.error = error;\n\nwhich overwrites the just-assigned -EFAULT with the positive residual.\nFUSE callers such as fuse_simple_request() test err \u003c 0 to detect\nfailure, so the positive value is interpreted as success and the\ncaller proceeds with an uninitialised or partial req-\u003eout.args.\n\nFix by assigning err = -EFAULT in the failure branch before jumping\nto out, so fuse_uring_req_end() receives a negative errno and sets\nreq-\u003eout.h.error to -EFAULT."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:49:13.891Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0483fffdeeb363f320e6bf5fc0f0306007507306"
        },
        {
          "url": "https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04"
        },
        {
          "url": "https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228"
        }
      ],
      "title": "fuse-uring: fix EFAULT clobber in fuse_uring_commit",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64264",
    "datePublished": "2026-07-25T08:49:13.891Z",
    "dateReserved": "2026-07-19T15:36:31.774Z",
    "dateUpdated": "2026-07-25T08:49:13.891Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64264",
      "date": "2026-07-26",
      "epss": "0.00198",
      "percentile": "0.09855"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64264\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-25T10:17:06.563\",\"lastModified\":\"2026-07-25T10:17:06.563\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nfuse-uring: fix EFAULT clobber in fuse_uring_commit\\n\\ncopy_from_user() returns the number of bytes not copied as an unsigned\\nresidual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit\\nstores that residual in ssize_t err, sets req-\u003eout.h.error to -EFAULT,\\nthen jumps to out: with err still holding the positive residual.\\n\\n    err = copy_from_user(\u0026req-\u003eout.h, \u0026ent-\u003eheaders-\u003ein_out,\\n                         sizeof(req-\u003eout.h));\\n    if (err) {\\n        req-\u003eout.h.error = -EFAULT;\\n        goto out;          /* err is the positive residual */\\n    }\\n    ...\\n    out:\\n        fuse_uring_req_end(ent, req, err);\\n\\nfuse_uring_req_end() then runs\\n\\n    if (error)\\n        req-\u003eout.h.error = error;\\n\\nwhich overwrites the just-assigned -EFAULT with the positive residual.\\nFUSE callers such as fuse_simple_request() test err \u003c 0 to detect\\nfailure, so the positive value is interpreted as success and the\\ncaller proceeds with an uninitialised or partial req-\u003eout.args.\\n\\nFix by assigning err = -EFAULT in the failure branch before jumping\\nto out, so fuse_uring_req_end() receives a negative errno and sets\\nreq-\u003eout.h.error to -EFAULT.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/fuse/dev_uring.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\"lessThan\":\"0483fffdeeb363f320e6bf5fc0f0306007507306\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\"lessThan\":\"fe604c08d874648a69187f6380e5c7858627dc04\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\"lessThan\":\"3a0a8bc51a13951c5141262bf770eeea3e0b6228\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/fuse/dev_uring.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.14\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.14\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0483fffdeeb363f320e6bf5fc0f0306007507306\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:47:02Z",
      "cve": "CVE-2026-64264",
      "id": "CVE-2026-64264",
      "initial_release_date": "2026-07-25T16:47:02Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64264",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64264.json",
      "version": "2"
    }
  }
}

GHSA-2MHJ-4M6M-6RJ5

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

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

fuse-uring: fix EFAULT clobber in fuse_uring_commit

copy_from_user() returns the number of bytes not copied as an unsigned residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit stores that residual in ssize_t err, sets req->out.h.error to -EFAULT, then jumps to out: with err still holding the positive residual.

err = copy_from_user(&req->out.h, &ent->headers->in_out,
                     sizeof(req->out.h));
if (err) {
    req->out.h.error = -EFAULT;
    goto out;          /* err is the positive residual */
}
...
out:
    fuse_uring_req_end(ent, req, err);

fuse_uring_req_end() then runs

if (error)
    req->out.h.error = error;

which overwrites the just-assigned -EFAULT with the positive residual. FUSE callers such as fuse_simple_request() test err < 0 to detect failure, so the positive value is interpreted as success and the caller proceeds with an uninitialised or partial req->out.args.

Fix by assigning err = -EFAULT in the failure branch before jumping to out, so fuse_uring_req_end() receives a negative errno and sets req->out.h.error to -EFAULT.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64264"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:06Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix EFAULT clobber in fuse_uring_commit\n\ncopy_from_user() returns the number of bytes not copied as an unsigned\nresidual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit\nstores that residual in ssize_t err, sets req-\u003eout.h.error to -EFAULT,\nthen jumps to out: with err still holding the positive residual.\n\n    err = copy_from_user(\u0026req-\u003eout.h, \u0026ent-\u003eheaders-\u003ein_out,\n                         sizeof(req-\u003eout.h));\n    if (err) {\n        req-\u003eout.h.error = -EFAULT;\n        goto out;          /* err is the positive residual */\n    }\n    ...\n    out:\n        fuse_uring_req_end(ent, req, err);\n\nfuse_uring_req_end() then runs\n\n    if (error)\n        req-\u003eout.h.error = error;\n\nwhich overwrites the just-assigned -EFAULT with the positive residual.\nFUSE callers such as fuse_simple_request() test err \u003c 0 to detect\nfailure, so the positive value is interpreted as success and the\ncaller proceeds with an uninitialised or partial req-\u003eout.args.\n\nFix by assigning err = -EFAULT in the failure branch before jumping\nto out, so fuse_uring_req_end() receives a negative errno and sets\nreq-\u003eout.h.error to -EFAULT.",
  "id": "GHSA-2mhj-4m6m-6rj5",
  "modified": "2026-07-25T12:31:28Z",
  "published": "2026-07-25T12:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64264"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0483fffdeeb363f320e6bf5fc0f0306007507306"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64264 (GCVE-0-2026-64264)

GHSA-2MHJ-4M6M-6RJ5

Tags

Sightings

Nomenclature