GHSA-4XG7-26QR-MCCF

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-27 06:30
VLAI
Details

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

fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns

In the analysis pass of $LogFile journal replay, log_replay() copies LCNs from each action log record into an existing Dirty Page Table (DPT) entry without bounding the destination index. A crafted NTFS image with DPT entry lcns_follow=1 and an action log record with lcns_follow=2 produces a kernel slab out-of-bounds write at mount time:

BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60 Write of size 8 at addr ffff8880095e1040 by task mount

Two attacker-controlled fields can drive j+i past the allocated page_lcns[] array:

  1. dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow.
  2. lrh->target_vcn may be smaller than dp->vcn, making the u64 subtraction wrap to a huge size_t.

Validate target VCN delta and per-record LCN count against the DPT entry capacity, bail via the existing out: cleanup label with -EINVAL.

This mirrors the bounds-check pattern added in commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in journal-replay file record check").

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-64432"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:27Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns\n\nIn the analysis pass of $LogFile journal replay, log_replay() copies\nLCNs from each action log record into an existing Dirty Page Table\n(DPT) entry without bounding the destination index. A crafted NTFS\nimage with DPT entry lcns_follow=1 and an action log record with\nlcns_follow=2 produces a kernel slab out-of-bounds write at mount\ntime:\n\n  BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60\n  Write of size 8 at addr ffff8880095e1040 by task mount\n\nTwo attacker-controlled fields can drive j+i past the allocated\npage_lcns[] array:\n\n  1. dp-\u003elcns_follow (capacity) can be smaller than lrh-\u003elcns_follow.\n  2. lrh-\u003etarget_vcn may be smaller than dp-\u003evcn, making the u64\n     subtraction wrap to a huge size_t.\n\nValidate target VCN delta and per-record LCN count against the\nDPT entry capacity, bail via the existing out: cleanup label with\n-EINVAL.\n\nThis mirrors the bounds-check pattern added in commit b2bc7c44ed17\n(\"fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot\")\nand commit 0ca0485e4b2e (\"fs/ntfs3: validate rec-\u003eused in\njournal-replay file record check\").",
  "id": "GHSA-4xg7-26qr-mccf",
  "modified": "2026-07-27T06:30:37Z",
  "published": "2026-07-25T12:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64432"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3aa96956ca2200674e2a8f9c23ec6ecd45e5010f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/57382ec6ac63b63dce2789e835fded28b698ae79"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/946046841013ebac8492ef49651c53638d7a9a6a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/964c3fae1dfc49dde5468eace940f199cda234e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c6f9e804f73ef809529865fbc7256dd189ff8c33"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cf28fc1658463d768657cf1c27a83980d4ba7ef2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f433acc85b86f327d03ba8b03a33c105c51053de"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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