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GHSA-GG5M-J9GF-RMHM

Vulnerability from github – Published: 2026-09-16 09:30 – Updated: 2026-09-16 09:30
VLAI
Details

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

fs/ntfs3: validate ef->size covers the record's name and value

When an EA record has a non-zero ef->size, ntfs_read_ea() only checks that the record fits in the remaining buffer (ea_size > bytes), not that ef->size is large enough to hold the record's own name_len + 1 + elength.

A crafted image can pass validation with, e.g., ef->size = 24 but elength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of the undersized record, reading past the kmalloc(info->size) allocation and leaking heap memory to userspace via getxattr():

BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302) Read of size 65535 at addr ffff888100794550 by task exploit __asan_memcpy (mm/kasan/shadow.c:105) ntfs_get_ea (fs/ntfs3/xattr.c:302) ntfs_getxattr (fs/ntfs3/xattr.c:848) __vfs_getxattr (fs/xattr.c:441) vfs_getxattr (fs/xattr.c:474) do_getxattr (fs/xattr.c:800) path_getxattrat (fs/xattr.c:868) do_syscall_64 (arch/x86/entry/syscall_64.c:94)

The buggy address is located 80 bytes inside of allocated 84-byte region in cache kmalloc-96

Compute the size the record needs and require ef->size to cover it.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-89779"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T09:17:08Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: validate ef-\u003esize covers the record\u0027s name and value\n\nWhen an EA record has a non-zero ef-\u003esize, ntfs_read_ea() only checks\nthat the record fits in the remaining buffer (ea_size \u003e bytes), not that\nef-\u003esize is large enough to hold the record\u0027s own name_len + 1 + elength.\n\nA crafted image can pass validation with, e.g., ef-\u003esize = 24 but\nelength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of\nthe undersized record, reading past the kmalloc(info-\u003esize) allocation\nand leaking heap memory to userspace via getxattr():\n\n BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302)\n Read of size 65535 at addr ffff888100794550 by task exploit\n  __asan_memcpy (mm/kasan/shadow.c:105)\n  ntfs_get_ea (fs/ntfs3/xattr.c:302)\n  ntfs_getxattr (fs/ntfs3/xattr.c:848)\n  __vfs_getxattr (fs/xattr.c:441)\n  vfs_getxattr (fs/xattr.c:474)\n  do_getxattr (fs/xattr.c:800)\n  path_getxattrat (fs/xattr.c:868)\n  do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n\n The buggy address is located 80 bytes inside of\n  allocated 84-byte region in cache kmalloc-96\n\nCompute the size the record needs and require ef-\u003esize to cover it.",
  "id": "GHSA-gg5m-j9gf-rmhm",
  "modified": "2026-09-16T09:30:30Z",
  "published": "2026-09-16T09:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89779"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/077df8464cf24f8ffc82fb6efec2ae600686e699"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/28a924c7e67e6d71abeb04860b61166fecb027fc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aab1880058ac767d3ea9388a9a7221c776c22c44"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b27e68ad818a4ca2cef8f35f97e75d756714c818"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c22f91d82cb9a29d22bdffdce6c803467984ad0c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c8a109c9e23a2c7fd548473dde728b2cb8188146"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d585ed08308909c7e6fefb4e8a258aeb29b19ff9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



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