Vulnerability-Lookup

GHSA-8QJ8-QF9J-579X

Vulnerability from github – Published: 2024-10-21 15:32 – Updated: 2025-11-04 00:31

Details

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

block, bfq: fix uaf for accessing waker_bfqq after splitting

After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe.

Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2024-49854"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-10-21T13:15:06Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix uaf for accessing waker_bfqq after splitting\n\nAfter commit 42c306ed7233 (\"block, bfq: don\u0027t break merge chain in\nbfq_split_bfqq()\"), if the current procress is the last holder of bfqq,\nthe bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and\nthen access bfqq-\u003ewaker_bfqq may trigger UAF. What\u0027s more, the waker_bfqq\nmay in the merge chain of bfqq, hence just recored waker_bfqq is still\nnot safe.\n\nFix the problem by adding a helper bfq_waker_bfqq() to check if\nbfqq-\u003ewaker_bfqq is in the merge chain, and current procress is the only\nholder.",
  "id": "GHSA-8qj8-qf9j-579x",
  "modified": "2025-11-04T00:31:39Z",
  "published": "2024-10-21T15:32:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49854"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0780451f03bf518bc032a7c584de8f92e2d39d7f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0b8bda0ff17156cd3f60944527c9d8c9f99f1583"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1ba0403ac6447f2d63914fb760c44a3b19c44eaf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63a07379fdb6c72450cb05294461c6016b8b7726"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cae58d19121a70329cf971359e2518c93fec04fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de0456460f2abf921e356ed2bd8da87a376680bd"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2024-49854 (GCVE-0-2024-49854)

Vulnerability from cvelistv5 – Published: 2024-10-21 12:18 – Updated: 2026-08-05 11:40

Title

block, bfq: fix uaf for accessing waker_bfqq after splitting

Summary

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

Severity

7.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-10-21 12:56 UTC

Assigner

Linux mitre root Scorecard

References

7 references

URL	Tags
https://git.kernel.org/stable/c/63a07379fdb6c7245…
https://git.kernel.org/stable/c/de0456460f2abf921…
https://git.kernel.org/stable/c/0780451f03bf518bc…
https://git.kernel.org/stable/c/0b8bda0ff17156cd3…
https://git.kernel.org/stable/c/cae58d19121a70329…
https://git.kernel.org/stable/c/1ba0403ac6447f2d6…
https://lists.debian.org/debian-lts-announce/2025…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e0c20d88b7dce85d2703bb6ba77bf359959675cd , < 63a07379fdb6c72450cb05294461c6016b8b7726 (git) Affected: de6c5e3a456019d2182e345730e59721714fa0b5 , < de0456460f2abf921e356ed2bd8da87a376680bd (git) Affected: 19f3bec2ac4be329b9bd12b18a989b867618d2d8 , < 0780451f03bf518bc032a7c584de8f92e2d39d7f (git) Affected: 13b3d0e8cb121f99b11918a0d4bcc1ce4647d352 , < 0b8bda0ff17156cd3f60944527c9d8c9f99f1583 (git) Affected: 4780f50ea50cfe8e89fc3747bf3dd155488433bb , < cae58d19121a70329cf971359e2518c93fec04fe (git) Affected: 42c306ed723321af4003b2a41bb73728cab54f85 , < 1ba0403ac6447f2d63914fb760c44a3b19c44eaf (git) Affected: 9e813033594b141f61ff0ef0cfaaef292564b041 (git) Affected: 3a5f45a4ad4e1fd36b0a998eef03d76a4f02a2a8 (git) Affected: 3630a18846c7853aa326d3b42fd0a855af7b41bc (git) Affected: 4.19.323 , < 4.20 (semver) Affected: 5.4.285 , < 5.5 (semver) Affected: 5.10.227 , < 5.11 (semver)
Linux	Linux

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                "id": "CVE-2024-49854",
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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.

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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GHSA-8QJ8-QF9J-579X

CVE-2024-49854 (GCVE-0-2024-49854)

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