CVE-2026-80956 (GCVE-0-2026-80956)
Vulnerability from cvelistv5
Published
2026-09-11 19:42
Modified
2026-10-19 08:45
Severity ?
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.
References
Impacted products
Vendor Product Version
Linux Linux Version: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0
Version: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0
Version: 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "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",
              "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",
                  "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": "2026-10-19T08:45:40.093Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "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"
      }
    }
  },
  "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": "2026-10-19T08:45:40.093Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.