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GHSA-FV7M-5JQ2-37CH

Vulnerability from github – Published: 2025-11-12 12:30 – Updated: 2025-11-12 12:30

Details

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

bpf: dont report verifier bug for missing bpf_scc_visit on speculative path

Syzbot generated a program that triggers a verifier_bug() call in maybe_exit_scc(). maybe_exit_scc() assumes that, when called for a state with insn_idx in some SCC, there should be an instance of struct bpf_scc_visit allocated for that SCC. Turns out the assumption does not hold for speculative execution paths. See example in the next patch.

maybe_scc_exit() is called from update_branch_counts() for states that reach branch count of zero, meaning that path exploration for a particular path is finished. Path exploration can finish in one of three ways: a. Verification error is found. In this case, update_branch_counts() is called only for non-speculative paths. b. Top level BPF_EXIT is reached. Such instructions are never a part of an SCC, so compute_scc_callchain() in maybe_scc_exit() will return false, and maybe_scc_exit() will return early. c. A checkpoint is reached and matched. Checkpoints are created by is_state_visited(), which calls maybe_enter_scc(), which allocates bpf_scc_visit instances for checkpoints within SCCs.

Hence, for non-speculative symbolic execution paths, the assumption still holds: if maybe_scc_exit() is called for a state within an SCC, bpf_scc_visit instance must exist.

This patch removes the verifier_bug() call for speculative paths.

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40143"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-11-12T11:15:44Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: dont report verifier bug for missing bpf_scc_visit on speculative path\n\nSyzbot generated a program that triggers a verifier_bug() call in\nmaybe_exit_scc(). maybe_exit_scc() assumes that, when called for a\nstate with insn_idx in some SCC, there should be an instance of struct\nbpf_scc_visit allocated for that SCC. Turns out the assumption does\nnot hold for speculative execution paths. See example in the next\npatch.\n\nmaybe_scc_exit() is called from update_branch_counts() for states that\nreach branch count of zero, meaning that path exploration for a\nparticular path is finished. Path exploration can finish in one of\nthree ways:\na. Verification error is found. In this case, update_branch_counts()\n   is called only for non-speculative paths.\nb. Top level BPF_EXIT is reached. Such instructions are never a part of\n   an SCC, so compute_scc_callchain() in maybe_scc_exit() will return\n   false, and maybe_scc_exit() will return early.\nc. A checkpoint is reached and matched. Checkpoints are created by\n   is_state_visited(), which calls maybe_enter_scc(), which allocates\n   bpf_scc_visit instances for checkpoints within SCCs.\n\nHence, for non-speculative symbolic execution paths, the assumption\nstill holds: if maybe_scc_exit() is called for a state within an SCC,\nbpf_scc_visit instance must exist.\n\nThis patch removes the verifier_bug() call for speculative paths.",
  "id": "GHSA-fv7m-5jq2-37ch",
  "modified": "2025-11-12T12:30:27Z",
  "published": "2025-11-12T12:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40143"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3861e7c4324aa20a632fb74eb3904114f6afdb57"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3c73d629ea1373af3c0c954d41fd1af555492e3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2025-40143 (GCVE-0-2025-40143)

Vulnerability from cvelistv5 – Published: 2025-11-12 10:23 – Updated: 2026-05-11 21:43

Title

bpf: dont report verifier bug for missing bpf_scc_visit on speculative path

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: dont report verifier bug for missing bpf_scc_visit on speculative path Syzbot generated a program that triggers a verifier_bug() call in maybe_exit_scc(). maybe_exit_scc() assumes that, when called for a state with insn_idx in some SCC, there should be an instance of struct bpf_scc_visit allocated for that SCC. Turns out the assumption does not hold for speculative execution paths. See example in the next patch. maybe_scc_exit() is called from update_branch_counts() for states that reach branch count of zero, meaning that path exploration for a particular path is finished. Path exploration can finish in one of three ways: a. Verification error is found. In this case, update_branch_counts() is called only for non-speculative paths. b. Top level BPF_EXIT is reached. Such instructions are never a part of an SCC, so compute_scc_callchain() in maybe_scc_exit() will return false, and maybe_scc_exit() will return early. c. A checkpoint is reached and matched. Checkpoints are created by is_state_visited(), which calls maybe_enter_scc(), which allocates bpf_scc_visit instances for checkpoints within SCCs. Hence, for non-speculative symbolic execution paths, the assumption still holds: if maybe_scc_exit() is called for a state within an SCC, bpf_scc_visit instance must exist. This patch removes the verifier_bug() call for speculative paths.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/3861e7c4324aa20a6…
https://git.kernel.org/stable/c/a3c73d629ea1373af…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c9e31900b54cadf5398dfb838c0a63effa1defec , < 3861e7c4324aa20a632fb74eb3904114f6afdb57 (git) Affected: c9e31900b54cadf5398dfb838c0a63effa1defec , < a3c73d629ea1373af3c0c954d41fd1af555492e3 (git)
Linux	Linux	Affected: 6.17 Unaffected: 0 , < 6.17 (semver) Unaffected: 6.17.3 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

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JSON

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{
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        {
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          "programFiles": [
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          "vendor": "Linux",
          "versions": [
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                },
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    "datePublished": "2025-11-12T10:23:25.489Z",
    "dateReserved": "2025-04-16T07:20:57.175Z",
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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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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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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