Vulnerability-Lookup

GHSA-2R45-HWHH-3HC3

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-11 21:31

Details

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

dm-pcache: only hand out initialized cache segments

get_cache_segment() scans the segment map up to cache->n_segs, the physical device segment count, but cache_segs_init() only initializes the first cache_info->n_segs segments. A crafted image with cache_info->n_segs smaller than the device count leaves the remaining pcache_cache_segment structs zeroed (segment.data == NULL), and the allocator can hand one to cache_kset_close(), which writes through the returned segment's data pointer with no NULL check.

Bound the allocator's search to cache_info->n_segs so only initialized segments are ever returned. A conforming cache sets n_segs equal to the device segment count, so this rejects nothing legitimate.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80956"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:01Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: only hand out initialized cache segments\n\nget_cache_segment() scans the segment map up to cache-\u003en_segs, the\nphysical device segment count, but cache_segs_init() only initializes\nthe first cache_info-\u003en_segs segments. A crafted image with\ncache_info-\u003en_segs smaller than the device count leaves the remaining\npcache_cache_segment structs zeroed (segment.data == NULL), and the\nallocator can hand one to cache_kset_close(), which writes through the\nreturned segment\u0027s data pointer with no NULL check.\n\nBound the allocator\u0027s search to cache_info-\u003en_segs so only initialized\nsegments are ever returned. A conforming cache sets n_segs equal to the\ndevice segment count, so this rejects nothing legitimate.",
  "id": "GHSA-2r45-hwhh-3hc3",
  "modified": "2026-09-11T21:31:21Z",
  "published": "2026-09-11T21:31:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80956"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-80956 (GCVE-0-2026-80956)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-11 19:42

Title

dm-pcache: only hand out initialized cache segments

Summary

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: only hand out initialized cache segments get_cache_segment() scans the segment map up to cache->n_segs, the physical device segment count, but cache_segs_init() only initializes the first cache_info->n_segs segments. A crafted image with cache_info->n_segs smaller than the device count leaves the remaining pcache_cache_segment structs zeroed (segment.data == NULL), and the allocator can hand one to cache_kset_close(), which writes through the returned segment's data pointer with no NULL check. Bound the allocator's search to cache_info->n_segs so only initialized segments are ever returned. A conforming cache sets n_segs equal to the device segment count, so this rejects nothing legitimate.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/83e3116283ed2c6a6…
https://git.kernel.org/stable/c/692037ae1a7cfacc2…
https://git.kernel.org/stable/c/2df0fc042e299bae3…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 , < 83e3116283ed2c6a6a1fa662862a4b4d7d2701a2 (git) Affected: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 , < 692037ae1a7cfacc2f0c22c6e034c1dfee0e553f (git) Affected: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 , < 2df0fc042e299bae3c0f60ea5cd2af9285658e9f (git)
Linux	Linux	Affected: 6.18 Unaffected: 0 , < 6.18 (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm-pcache/cache_segment.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "83e3116283ed2c6a6a1fa662862a4b4d7d2701a2",
              "status": "affected",
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "versionType": "git"
            },
            {
              "lessThan": "692037ae1a7cfacc2f0c22c6e034c1dfee0e553f",
              "status": "affected",
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "versionType": "git"
            },
            {
              "lessThan": "2df0fc042e299bae3c0f60ea5cd2af9285658e9f",
              "status": "affected",
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm-pcache/cache_segment.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "lessThan": "6.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: only hand out initialized cache segments\n\nget_cache_segment() scans the segment map up to cache-\u003en_segs, the\nphysical device segment count, but cache_segs_init() only initializes\nthe first cache_info-\u003en_segs segments. A crafted image with\ncache_info-\u003en_segs smaller than the device count leaves the remaining\npcache_cache_segment structs zeroed (segment.data == NULL), and the\nallocator can hand one to cache_kset_close(), which writes through the\nreturned segment\u0027s data pointer with no NULL check.\n\nBound the allocator\u0027s search to cache_info-\u003en_segs so only initialized\nsegments are ever returned. A conforming cache sets n_segs equal to the\ndevice segment count, so this rejects nothing legitimate."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:42:24.541Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2"
        },
        {
          "url": "https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f"
        }
      ],
      "title": "dm-pcache: only hand out initialized cache segments",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80956",
    "datePublished": "2026-09-11T19:42:24.541Z",
    "dateReserved": "2026-08-26T14:34:25.804Z",
    "dateUpdated": "2026-09-11T19:42:24.541Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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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