Vulnerability-Lookup

GHSA-2CXW-35RJ-WXQ7

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-15 21:31

Details

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

bpf: reject direct access to nullable PTR_TO_BUF pointers

check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check.

Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference.

Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern.

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-2026-43333"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T14:16:43Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject direct access to nullable PTR_TO_BUF pointers\n\ncheck_mem_access() matches PTR_TO_BUF via base_type() which strips\nPTR_MAYBE_NULL, allowing direct dereference without a null check.\n\nMap iterator ctx-\u003ekey and ctx-\u003evalue are PTR_TO_BUF | PTR_MAYBE_NULL.\nOn stop callbacks these are NULL, causing a kernel NULL dereference.\n\nAdd a type_may_be_null() guard to the PTR_TO_BUF branch, matching the\nexisting PTR_TO_BTF_ID pattern.",
  "id": "GHSA-2cxw-35rj-wxq7",
  "modified": "2026-05-15T21:31:30Z",
  "published": "2026-05-08T15:31:23Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43333"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/10bc4a4dcded509c5d5c67d497900c3922c604cd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/70abd9d118da2f56beb4ec22e3a29becae373535"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b0db1accbc7395657c2b79db59fa9fae0d6656f3"
    }
  ],
  "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-2026-43333 (GCVE-0-2026-43333)

Vulnerability from cvelistv5 – Published: 2026-05-08 13:31 – Updated: 2026-05-23 16:06

Title

bpf: reject direct access to nullable PTR_TO_BUF pointers

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: reject direct access to nullable PTR_TO_BUF pointers check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check. Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference. Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern.

Severity

No CVSS data available.

Assigner

Linux

References

7 references

URL	Tags
https://git.kernel.org/stable/c/10bc4a4dcded509c5…
https://git.kernel.org/stable/c/21a10c06ffae24cb0…
https://git.kernel.org/stable/c/8755066f7bd0f4ac4…
https://git.kernel.org/stable/c/70abd9d118da2f56b…
https://git.kernel.org/stable/c/63276547debc4d8a7…
https://git.kernel.org/stable/c/4f6c99dc0420f1a3d…
https://git.kernel.org/stable/c/b0db1accbc7395657…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b453361384c2db1c703dacb806d5fd36aec4ceca , < 10bc4a4dcded509c5d5c67d497900c3922c604cd (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < 21a10c06ffae24cb01fd174a7ab7736001d2ea56 (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < 8755066f7bd0f4ac46a29d1708c7b20894539252 (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < 70abd9d118da2f56beb4ec22e3a29becae373535 (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < 63276547debc4d8a73eefb2c5273b2a905c961b0 (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < 4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09 (git) Affected: 20b2aff4bc15bda809f994761d5719827d66c0b4 , < b0db1accbc7395657c2b79db59fa9fae0d6656f3 (git) Affected: e982070f8970bb62e69ed7c9cafff886ed200349 (git) Affected: 5.15.37 , < 5.15.203 (semver) Affected: 5.16.11 , < 5.17 (semver)
Linux	Linux	Affected: 5.17 Unaffected: 0 , < 5.17 (semver) Unaffected: 5.15.203 , ≤ 5.15.* (semver) Unaffected: 6.1.168 , ≤ 6.1.* (semver) Unaffected: 6.6.134 , ≤ 6.6.* (semver) Unaffected: 6.12.81 , ≤ 6.12.* (semver) Unaffected: 6.18.22 , ≤ 6.18.* (semver) Unaffected: 6.19.12 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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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.

Action not permitted

GHSA-2CXW-35RJ-WXQ7

CVE-2026-43333 (GCVE-0-2026-43333)

Tags

Sightings

Nomenclature