{
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          "type": "GIT"
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    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
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              "introduced": "0"
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            {
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        },
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          ],
          "type": "ECOSYSTEM"
        },
        {
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            }
          ],
          "type": "ECOSYSTEM"
        },
        {
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            },
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          ],
          "type": "ECOSYSTEM"
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        {
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          "type": "ECOSYSTEM"
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  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68099.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL\n\ncheck_add_overflow() unconditionally writes the truncated sum into *d\neven on overflow, per its contract in include/linux/overflow.h.\nThe four check_add_overflow() guards in set_posix_acl_entries_dacl()\nand set_ntacl_dacl() break out of the ACE-building loops on overflow,\nbut the truncated *size is then consumed downstream at the end of\nset_ntacl_dacl():\n\n    pndacl-\u003esize = cpu_to_le16(le16_to_cpu(pndacl-\u003esize) + size);\n\nThis produces an on-wire NT ACL whose pndacl-\u003esize under-reports the\nbytes actually written by the preceding fill_ace_for_sid()/memcpy()\ncalls, yielding a malformed ACL that can trigger out-of-bounds reads\nwhen re-parsed by clients or ksmbd itself.\n\nRestore *size to its pre-addition value on each overflow branch (via\n`*size -= ace_sz` / `size -= nt_ace_size`) so that after the break,\n*size once again holds the cumulative size of the successfully-written\nACEs. The committed ACL is then truncated-but-self-consistent rather\nthan malformed.\n\nThe ksmbd DACL builders are the only check_add_overflow() sites found\nwhere an overflow path breaks out of a loop and the destination value\nis consumed afterward. The other nearby break-style cases either\nreturn -EINVAL on overflow (transport_ipc.c) or break without\nconsuming the overflowed destination value afterward (buildid.c).",
  "id": "CVE-2026-68099",
  "modified": "2026-08-25T03:51:54.535715655Z",
  "published": "2026-08-10T11:58:13.940Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0bf38372821b1526f31538a7d9811844c55c7f38"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/847ecd4eb3c117c3d2f13f1e7ab506543aad8183"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8f3a7a499a7d9bb1c0f33fe78c4a4594d7e307f4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bbf0a8e931204ecdab494a88d43b0a24a04285c5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bc90144ce8bb7fcf05ad9417c7adb4e9509d9e13"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f4fcd0c1a243d449307b887fafee23921e9db5ab"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68099.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68099"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL"
}