Vulnerability-Lookup

GHSA-4P4J-8FXF-MVHP

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-11 21:31

Details

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

fuse: copy request headers via a stack buffer for io-uring

The fuse-io-uring transport copies req->in.h out to the ring in fuse_uring_copy_to_ring() and req->out.h back in fuse_uring_commit(). Both headers live inside the fuse_request slab object, whose cache (fuse_req_cachep) is created without a usercopy whitelist, so copying them directly to/from userspace trips CONFIG_HARDENED_USERCOPY and panics:

usercopy: Kernel memory exposure attempt detected from SLUB object 'fuse_request' (offset 56, size 40)! kernel BUG at mm/usercopy.c:102! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:usercopy_abort (mm/usercopy.c:90) Call Trace: __check_heap_object (mm/slub.c:8268) __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223) copy_header_to_ring (fs/fuse/dev_uring.c:618) fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785) fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306) tctx_task_work_run (io_uring/tw.c:96) task_work_run (kernel/task_work.c:233) io_run_task_work (io_uring/tw.h:84) io_cqring_wait (io_uring/wait.c:278) __do_sys_io_uring_enter (io_uring/io_uring.c:2685) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

Bounce both headers through an on-stack copy so the usercopy touches stack memory, not the slab object.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-80946"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:00Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: copy request headers via a stack buffer for io-uring\n\nThe fuse-io-uring transport copies req-\u003ein.h out to the ring in\nfuse_uring_copy_to_ring() and req-\u003eout.h back in fuse_uring_commit().\nBoth headers live inside the fuse_request slab object, whose cache\n(fuse_req_cachep) is created without a usercopy whitelist, so copying\nthem directly to/from userspace trips CONFIG_HARDENED_USERCOPY and\npanics:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  \u0027fuse_request\u0027 (offset 56, size 40)!\n  kernel BUG at mm/usercopy.c:102!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n  RIP: 0010:usercopy_abort (mm/usercopy.c:90)\n  Call Trace:\n   __check_heap_object (mm/slub.c:8268)\n   __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223)\n   copy_header_to_ring (fs/fuse/dev_uring.c:618)\n   fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785)\n   fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306)\n   tctx_task_work_run (io_uring/tw.c:96)\n   task_work_run (kernel/task_work.c:233)\n   io_run_task_work (io_uring/tw.h:84)\n   io_cqring_wait (io_uring/wait.c:278)\n   __do_sys_io_uring_enter (io_uring/io_uring.c:2685)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nBounce both headers through an on-stack copy so the usercopy touches\nstack memory, not the slab object.",
  "id": "GHSA-4p4j-8fxf-mvhp",
  "modified": "2026-09-11T21:31:20Z",
  "published": "2026-09-11T21:31:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80946"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-80946 (GCVE-0-2026-80946)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-11 19:42

Title

fuse: copy request headers via a stack buffer for io-uring

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse: copy request headers via a stack buffer for io-uring The fuse-io-uring transport copies req->in.h out to the ring in fuse_uring_copy_to_ring() and req->out.h back in fuse_uring_commit(). Both headers live inside the fuse_request slab object, whose cache (fuse_req_cachep) is created without a usercopy whitelist, so copying them directly to/from userspace trips CONFIG_HARDENED_USERCOPY and panics: usercopy: Kernel memory exposure attempt detected from SLUB object 'fuse_request' (offset 56, size 40)! kernel BUG at mm/usercopy.c:102! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:usercopy_abort (mm/usercopy.c:90) Call Trace: __check_heap_object (mm/slub.c:8268) __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223) copy_header_to_ring (fs/fuse/dev_uring.c:618) fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785) fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306) tctx_task_work_run (io_uring/tw.c:96) task_work_run (kernel/task_work.c:233) io_run_task_work (io_uring/tw.h:84) io_cqring_wait (io_uring/wait.c:278) __do_sys_io_uring_enter (io_uring/io_uring.c:2685) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Bounce both headers through an on-stack copy so the usercopy touches stack memory, not the slab object.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/194d0fb0ea4720535…
https://git.kernel.org/stable/c/a47a416ff68d706dc…
https://git.kernel.org/stable/c/fd10f40af314f07b6…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < 194d0fb0ea4720535ff3168c9d04c7632cec7071 (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < a47a416ff68d706dc3327ab583f86b9ee757358b (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < fd10f40af314f07b6d6e028b1ca25c8b49903aab (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 6.18.51 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "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": "194d0fb0ea4720535ff3168c9d04c7632cec7071",
              "status": "affected",
              "version": "c090c8abae4b6b77a1bee116aa6c385456ebef96",
              "versionType": "git"
            },
            {
              "lessThan": "a47a416ff68d706dc3327ab583f86b9ee757358b",
              "status": "affected",
              "version": "c090c8abae4b6b77a1bee116aa6c385456ebef96",
              "versionType": "git"
            },
            {
              "lessThan": "fd10f40af314f07b6d6e028b1ca25c8b49903aab",
              "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": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.51",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: copy request headers via a stack buffer for io-uring\n\nThe fuse-io-uring transport copies req-\u003ein.h out to the ring in\nfuse_uring_copy_to_ring() and req-\u003eout.h back in fuse_uring_commit().\nBoth headers live inside the fuse_request slab object, whose cache\n(fuse_req_cachep) is created without a usercopy whitelist, so copying\nthem directly to/from userspace trips CONFIG_HARDENED_USERCOPY and\npanics:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  \u0027fuse_request\u0027 (offset 56, size 40)!\n  kernel BUG at mm/usercopy.c:102!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n  RIP: 0010:usercopy_abort (mm/usercopy.c:90)\n  Call Trace:\n   __check_heap_object (mm/slub.c:8268)\n   __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223)\n   copy_header_to_ring (fs/fuse/dev_uring.c:618)\n   fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785)\n   fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306)\n   tctx_task_work_run (io_uring/tw.c:96)\n   task_work_run (kernel/task_work.c:233)\n   io_run_task_work (io_uring/tw.h:84)\n   io_cqring_wait (io_uring/wait.c:278)\n   __do_sys_io_uring_enter (io_uring/io_uring.c:2685)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nBounce both headers through an on-stack copy so the usercopy touches\nstack memory, not the slab object."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:42:17.576Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071"
        },
        {
          "url": "https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b"
        },
        {
          "url": "https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab"
        }
      ],
      "title": "fuse: copy request headers via a stack buffer for io-uring",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80946",
    "datePublished": "2026-09-11T19:42:17.576Z",
    "dateReserved": "2026-08-26T14:34:25.803Z",
    "dateUpdated": "2026-09-11T19:42:17.576Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.