Vulnerability-Lookup

GHSA-MX29-FW97-M6GR

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33

Details

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

bpf: Require frozen map for calculating map hash

Currently, bpf_map_get_info_by_fd calculates and caches the hash of the map regardless of the map's frozen state.

This leads to a TOCTOU bug where userspace can call BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map contents before freezing.

Therefore, a trusted loader can be tricked into verifying the stale hash while loading the modified contents.

Fix this by returning -EPERM if the map is not frozen when the hash is requested. This ensures the hash is only generated for the final, immutable state of the map.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-45927"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:08Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Require frozen map for calculating map hash\n\nCurrently, bpf_map_get_info_by_fd calculates and caches the hash of the\nmap regardless of the map\u0027s frozen state.\n\nThis leads to a TOCTOU bug where userspace can call\nBPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map\ncontents before freezing.\n\nTherefore, a trusted loader can be tricked into verifying the stale hash\nwhile loading the modified contents.\n\nFix this by returning -EPERM if the map is not frozen when the hash is\nrequested. This ensures the hash is only generated for the final,\nimmutable state of the map.",
  "id": "GHSA-mx29-fw97-m6gr",
  "modified": "2026-05-27T15:33:16Z",
  "published": "2026-05-27T15:33:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45927"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7752d36343862323bbeea4ce3adf0ec2ed86e122"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a2c86aa621c22f2a7e26c654f936d65cfff0aa91"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f415e114b58fe02c41191e47f24bdabb438daf72"
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}

CVE-2026-45927 (GCVE-0-2026-45927)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:17 – Updated: 2026-05-27 12:17

Title

bpf: Require frozen map for calculating map hash

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Require frozen map for calculating map hash Currently, bpf_map_get_info_by_fd calculates and caches the hash of the map regardless of the map's frozen state. This leads to a TOCTOU bug where userspace can call BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map contents before freezing. Therefore, a trusted loader can be tricked into verifying the stale hash while loading the modified contents. Fix this by returning -EPERM if the map is not frozen when the hash is requested. This ensures the hash is only generated for the final, immutable state of the map.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/7752d36343862323b…
https://git.kernel.org/stable/c/f415e114b58fe02c4…
https://git.kernel.org/stable/c/a2c86aa621c22f2a7…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: ea2e6467ac36bf3d785defc89e58269b15d182f7 , < 7752d36343862323bbeea4ce3adf0ec2ed86e122 (git) Affected: ea2e6467ac36bf3d785defc89e58269b15d182f7 , < f415e114b58fe02c41191e47f24bdabb438daf72 (git) Affected: ea2e6467ac36bf3d785defc89e58269b15d182f7 , < a2c86aa621c22f2a7e26c654f936d65cfff0aa91 (git)
Linux	Linux	Affected: 6.18 Unaffected: 0 , < 6.18 (semver) Unaffected: 6.18.14 , ≤ 6.18.* (semver) Unaffected: 6.19.4 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
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          "versions": [
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                }
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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-MX29-FW97-M6GR

CVE-2026-45927 (GCVE-0-2026-45927)

Tags

Sightings

Nomenclature