Vulnerability-Lookup

GHSA-VQQ3-2X9H-9PMG

Vulnerability from github – Published: 2026-09-17 18:32 – Updated: 2026-09-17 18:32

Details

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

bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max

check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field:

meta->r0_size = reg->var_off.value; ... regs[BPF_REG_0].mem_size = meta.r0_size;

regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound.

Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-93125"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:18:07Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg-\u003evar_off.value into meta-\u003er0_size, a u64,\nand does not bound it. check_kfunc_call() later copies that value into\nthe returned register\u0027s mem_size field:\n\n  meta-\u003er0_size = reg-\u003evar_off.value;\n  ...\n  regs[BPF_REG_0].mem_size = meta.r0_size;\n\nregs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set\ngets truncated instead of causing a load-time rejection, so the verifier\nrecords a PTR_TO_MEM register with an approximately 4 GiB mem_size for\nwhatever allocation the kfunc returned. A later access check against\nthat register uses the truncated, wrong bound.\n\nReject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the\npoint meta-\u003er0_size is set.",
  "id": "GHSA-vqq3-2x9h-9pmg",
  "modified": "2026-09-17T18:32:11Z",
  "published": "2026-09-17T18:32:11Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93125"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2aaf67f0516fde29620d0edfc29c01b9ea7ad430"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/56a3846830ac95a472297d0cbba75cbff29540bb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-93125 (GCVE-0-2026-93125)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:11 – Updated: 2026-09-17 16:11

Title

bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field: meta->r0_size = reg->var_off.value; ... regs[BPF_REG_0].mem_size = meta.r0_size; regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound. Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/56a3846830ac95a47…
https://git.kernel.org/stable/c/2aaf67f0516fde296…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae , < 56a3846830ac95a472297d0cbba75cbff29540bb (git) Affected: eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae , < 2aaf67f0516fde29620d0edfc29c01b9ea7ad430 (git)
Linux	Linux	Affected: 6.1 Unaffected: 0 , < 6.1 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
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        {
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          "programFiles": [
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "status": "affected",
              "version": "eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae",
              "versionType": "git"
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          "product": "Linux",
          "programFiles": [
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              "version": "7.2.6",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
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          "nodes": [
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              "cpeMatch": [
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                  "vulnerable": true
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg-\u003evar_off.value into meta-\u003er0_size, a u64,\nand does not bound it. check_kfunc_call() later copies that value into\nthe returned register\u0027s mem_size field:\n\n  meta-\u003er0_size = reg-\u003evar_off.value;\n  ...\n  regs[BPF_REG_0].mem_size = meta.r0_size;\n\nregs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set\ngets truncated instead of causing a load-time rejection, so the verifier\nrecords a PTR_TO_MEM register with an approximately 4 GiB mem_size for\nwhatever allocation the kfunc returned. A later access check against\nthat register uses the truncated, wrong bound.\n\nReject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the\npoint meta-\u003er0_size is set."
        }
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        "dateUpdated": "2026-09-17T16:11:29.895Z",
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    "datePublished": "2026-09-17T16:11:29.895Z",
    "dateReserved": "2026-09-17T16:02:15.087Z",
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    "state": "PUBLISHED"
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}

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.

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