CVE-2026-80960

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate on-media seg_num against the cache device size seg_num is read from the crc32c-only superblock, so whoever supplies the cache device on a table load (CAP_SYS_ADMIN) controls it. It sizes cache->segments[] and is the value every later on-media segment id is bounded against, yet it is never checked against the device. Because cache_dev->mapping is the direct map of the pmem, CACHE_DEV_SEGMENT() for a segment id past the device resolves to ordinary kernel memory beyond the mapping; a new-cache init reaching such an id has cache_seg_init() -> cache_dev_zero_range() memset() 12 KiB over that memory -- an out-of-bounds write into the kernel heap at table load. A zero seg_num makes the segment allocations ZERO_SIZE_PTR. Reject a seg_num that is zero, larger than the device can hold, or larger than PCACHE_CACHE_SEGS_MAX before it is used.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:19:01.863000

Last modified

2026-10-19 09:17:27.510000

View original CVE JSON

{
  "id": "CVE-2026-80960",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:01.863",
  "lastModified": "2026-10-19T09:17:27.510",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: validate on-media seg_num against the cache device size\n\nseg_num is read from the crc32c-only superblock, so whoever supplies the\ncache device on a table load (CAP_SYS_ADMIN) controls it. It sizes\ncache->segments[] and is the value every later on-media segment id is\nbounded against, yet it is never checked against the device. Because\ncache_dev->mapping is the direct map of the pmem, CACHE_DEV_SEGMENT() for\na segment id past the device resolves to ordinary kernel memory beyond\nthe mapping; a new-cache init reaching such an id has cache_seg_init() ->\ncache_dev_zero_range() memset() 12 KiB over that memory -- an\nout-of-bounds write into the kernel heap at table load. A zero seg_num\nmakes the segment allocations ZERO_SIZE_PTR.\n\nReject a seg_num that is zero, larger than the device can hold, or larger\nthan PCACHE_CACHE_SEGS_MAX before it is used."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/md/dm-pcache/cache_dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "lessThan": "91b93fe5cf4d62d5ecc642a6c8f15a3c11b00e3c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "lessThan": "e889c0ee81165fc90aad2979b51f930f77895703",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
              "lessThan": "62d92e45abe9e087370f9fc5d876b95673aced34",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/md/dm-pcache/cache_dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.18",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.18",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/62d92e45abe9e087370f9fc5d876b95673aced34",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/91b93fe5cf4d62d5ecc642a6c8f15a3c11b00e3c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e889c0ee81165fc90aad2979b51f930f77895703",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}