GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

GHSA-GG95-XC64-46GM

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33
VLAI
Details

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

dm-log: fix a bitset_size overflow on 32bit machines

Commit c20e36b7631d ("dm log: fix out-of-bounds write due to region_count overflow") made sure that region_count could fit in an unsigned int. But the bitmap memory isn't allocated based on region_count. It uses bitset_size (a size_t variable). The first step of calculating bitset_size is to set it to region_count, rounded up to a multiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG smaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit architecture, this will make bitset_size wrap around to 0 and fail, despite region_count being valid.

Since bitset_size gets divided by 8, it can hold any valid region_count. It just needs a special case to handle the rollover. If it is 0, the value rolled over, and bitset size should be set to the number of bytes needed to hold 2^32 bits.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-72105"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:24Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-log: fix a bitset_size overflow on 32bit machines\n\nCommit c20e36b7631d (\"dm log: fix out-of-bounds write due to\nregion_count overflow\") made sure that region_count could fit in an\nunsigned int. But the bitmap memory isn\u0027t allocated based on\nregion_count. It uses bitset_size (a size_t variable). The first step of\ncalculating bitset_size is to set it to region_count, rounded up to a\nmultiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG\nsmaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit\narchitecture, this will make bitset_size wrap around to 0 and fail,\ndespite region_count being valid.\n\nSince bitset_size gets divided by 8, it can hold any valid region_count.\nIt just needs a special case to handle the rollover. If it is 0, the\nvalue rolled over, and bitset size should be set to the number of bytes\nneeded to hold 2^32 bits.",
  "id": "GHSA-gg95-xc64-46gm",
  "modified": "2026-08-17T06:33:10Z",
  "published": "2026-08-15T06:32:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72105"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c3412b584e1fb6c665ff33ba7259253bc0082cb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4b0de5a3ac1fd42acb0dc1f80ac5747e3287d723"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/567602fa72d57169365cbc589e0b8c3be900636d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/79feb87ab2396d49b9b65e4bb815d33cc71cba47"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9743132a41f4d9d0e54c5f2adcb821b04796bab1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cdc4ddf9db2cb79f4ab86b1a509b7ac21b0b6cf5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d05e0edfecf5260e6dddd28b2f0cce02bfc6ed7a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e0b0163a65758ec3a2361ae1cea407898c27f21e"
    }
  ],
  "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"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.