Vulnerability-Lookup

GHSA-W7V4-JWP5-GR92

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-09-04 15:35

Details

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

io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE

NOP file-acquisition support choses between a fixed (registered) file and a normal fget()'d file based on its own IORING_NOP_FIXED_FILE flag in sqe->nop_flags. However, a request's REQ_F_FIXED_FILE is set independently from the generic IOSQE_FIXED_FILE sqe flag during request init, before the issue handler runs.

If a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is set) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path and grabs a real reference via io_file_get_normal(). On completion, io_put_file() only drops the reference when REQ_F_FIXED_FILE is clear, so the fget()'d file is never released and leaks:

BUG: memory leak unreferenced object 0xffff88800f42c240 (size 176): kmem_cache_alloc_noprof+0x358/0x440 alloc_empty_file+0x57/0x180 path_openat+0x44/0x1e50 do_file_open+0x121/0x200 do_sys_openat2+0xa7/0x150 __x64_sys_openat+0x82/0xf0

Decide between fixed and normal file acquisition from REQ_F_FIXED_FILE, the same way io_assign_file() does for every other opcode, and fold IORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64426"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:26Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/nop: fix file reference leak with IOSQE_FIXED_FILE\n\nNOP file-acquisition support choses between a fixed (registered) file and\na normal fget()\u0027d file based on its own IORING_NOP_FIXED_FILE flag in\nsqe-\u003enop_flags. However, a request\u0027s REQ_F_FIXED_FILE is set\nindependently from the generic IOSQE_FIXED_FILE sqe flag during request\ninit, before the issue handler runs.\n\nIf a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is\nset) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path\nand grabs a real reference via io_file_get_normal(). On completion,\nio_put_file() only drops the reference when REQ_F_FIXED_FILE is clear,\nso the fget()\u0027d file is never released and leaks:\n\n  BUG: memory leak\n  unreferenced object 0xffff88800f42c240 (size 176):\n    kmem_cache_alloc_noprof+0x358/0x440\n    alloc_empty_file+0x57/0x180\n    path_openat+0x44/0x1e50\n    do_file_open+0x121/0x200\n    do_sys_openat2+0xa7/0x150\n    __x64_sys_openat+0x82/0xf0\n\nDecide between fixed and normal file acquisition from REQ_F_FIXED_FILE,\nthe same way io_assign_file() does for every other opcode, and fold\nIORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.",
  "id": "GHSA-w7v4-jwp5-gr92",
  "modified": "2026-09-04T15:35:55Z",
  "published": "2026-07-25T12:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64426"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2564ca2e31bd8ee8348362941af2ee4671e487ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/722869fcff598fad20d5ab79c305897a7534708b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7267717f35787167fcce4bc14f6ef3fa06682dcf"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64426 (GCVE-0-2026-64426)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-08-17 04:55

Title

io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE

Summary

In the Linux kernel, the following vulnerability has been resolved: io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE NOP file-acquisition support choses between a fixed (registered) file and a normal fget()'d file based on its own IORING_NOP_FIXED_FILE flag in sqe->nop_flags. However, a request's REQ_F_FIXED_FILE is set independently from the generic IOSQE_FIXED_FILE sqe flag during request init, before the issue handler runs. If a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is set) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path and grabs a real reference via io_file_get_normal(). On completion, io_put_file() only drops the reference when REQ_F_FIXED_FILE is clear, so the fget()'d file is never released and leaks: BUG: memory leak unreferenced object 0xffff88800f42c240 (size 176): kmem_cache_alloc_noprof+0x358/0x440 alloc_empty_file+0x57/0x180 path_openat+0x44/0x1e50 do_file_open+0x121/0x200 do_sys_openat2+0xa7/0x150 __x64_sys_openat+0x82/0xf0 Decide between fixed and normal file acquisition from REQ_F_FIXED_FILE, the same way io_assign_file() does for every other opcode, and fold IORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/722869fcff598fad2…
https://git.kernel.org/stable/c/7267717f35787167f…
https://git.kernel.org/stable/c/2564ca2e31bd8ee83…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a85f31052bce52111b4e9d5a536003481d0421d0 , < 722869fcff598fad20d5ab79c305897a7534708b (git) Affected: a85f31052bce52111b4e9d5a536003481d0421d0 , < 7267717f35787167fcce4bc14f6ef3fa06682dcf (git) Affected: a85f31052bce52111b4e9d5a536003481d0421d0 , < 2564ca2e31bd8ee8348362941af2ee4671e487ca (git)
Linux	Linux	Affected: 6.13 Unaffected: 0 , < 6.13 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/nop.c"
          ],
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "a85f31052bce52111b4e9d5a536003481d0421d0",
              "versionType": "git"
            },
            {
              "lessThan": "7267717f35787167fcce4bc14f6ef3fa06682dcf",
              "status": "affected",
              "version": "a85f31052bce52111b4e9d5a536003481d0421d0",
              "versionType": "git"
            },
            {
              "lessThan": "2564ca2e31bd8ee8348362941af2ee4671e487ca",
              "status": "affected",
              "version": "a85f31052bce52111b4e9d5a536003481d0421d0",
              "versionType": "git"
            }
          ]
        },
        {
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          "product": "Linux",
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "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:*:*:*:*:*:*:*:*",
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                }
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              "negate": false,
              "operator": "OR"
            }
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        }
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/nop: fix file reference leak with IOSQE_FIXED_FILE\n\nNOP file-acquisition support choses between a fixed (registered) file and\na normal fget()\u0027d file based on its own IORING_NOP_FIXED_FILE flag in\nsqe-\u003enop_flags. However, a request\u0027s REQ_F_FIXED_FILE is set\nindependently from the generic IOSQE_FIXED_FILE sqe flag during request\ninit, before the issue handler runs.\n\nIf a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is\nset) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path\nand grabs a real reference via io_file_get_normal(). On completion,\nio_put_file() only drops the reference when REQ_F_FIXED_FILE is clear,\nso the fget()\u0027d file is never released and leaks:\n\n  BUG: memory leak\n  unreferenced object 0xffff88800f42c240 (size 176):\n    kmem_cache_alloc_noprof+0x358/0x440\n    alloc_empty_file+0x57/0x180\n    path_openat+0x44/0x1e50\n    do_file_open+0x121/0x200\n    do_sys_openat2+0xa7/0x150\n    __x64_sys_openat+0x82/0xf0\n\nDecide between fixed and normal file acquisition from REQ_F_FIXED_FILE,\nthe same way io_assign_file() does for every other opcode, and fold\nIORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time."
        }
      ],
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        "dateUpdated": "2026-08-17T04:55:26.542Z",
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        },
        {
          "url": "https://git.kernel.org/stable/c/2564ca2e31bd8ee8348362941af2ee4671e487ca"
        }
      ],
      "title": "io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE",
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      }
    }
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  "cveMetadata": {
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    "datePublished": "2026-07-25T08:51:03.867Z",
    "dateReserved": "2026-07-19T15:36:31.787Z",
    "dateUpdated": "2026-08-17T04:55:26.542Z",
    "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.
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