{
  "cveId": "CVE-2025-40025",
  "url": "https://patchblox.com/security/cve/CVE-2025-40025",
  "summary": "CVE-2025-40025 is fixed in linux on 1 platform by DEBIAN-CVE-2025-40025 (version 6.17.6-1), released October 28, 2025. It is not reported as exploited. Patch Radar priority: High.",
  "title": "f2fs: fix to do sanity check on node footer for non inode dnode",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix to do sanity check on node footer for non inode dnode  As syzbot reported below:  ------------[ cut here ]------------ kernel BUG at fs/f2fs/file.c:1243! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full) RIP: 0010:f2fs_truncate_hole\u002B0x69e/0x6c0 fs/f2fs/file.c:1243 Call Trace:  \u003CTASK\u003E  f2fs_punch_hole\u002B0x2db/0x330 fs/f2fs/file.c:1306  f2fs_fallocate\u002B0x546/0x990 fs/f2fs/file.c:2018  vfs_fallocate\u002B0x666/0x7e0 fs/open.c:342  ksys_fallocate fs/open.c:366 [inline]  __do_sys_fallocate fs/open.c:371 [inline]  __se_sys_fallocate fs/open.c:369 [inline]  __x64_sys_fallocate\u002B0xc0/0x110 fs/open.c:369  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]  do_syscall_64\u002B0xfa/0x3b0 arch/x86/entry/syscall_64.c:94  entry_SYSCALL_64_after_hwframe\u002B0x77/0x7f RIP: 0033:0x7f1e65f8ebe9  w/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent truncation range in direct node in f2fs_truncate_hole().  The root cause is: a non-inode dnode may has the same footer.ino and footer.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE() may return wrong blkaddr count which may be 923 typically, by chance, dn.ofs_in_node is equal to 923, then count can be calculated to 0 in below statement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...).  \tcount = min(end_offset - dn.ofs_in_node, pg_end - pg_start);  This patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing passing the new_type to sanity_check_node_footer in f2fs_get_node_folio() to detect corruption that a non-inode dnode has the same footer.ino and footer.nid.  Scripts to reproduce: mkfs.f2fs -f /dev/vdb mount /dev/vdb /mnt/f2fs touch /mnt/f2fs/foo touch /mnt/f2fs/bar dd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8 umount /mnt/f2fs inject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb mount /dev/vdb /mnt/f2fs xfs_io /mnt/f2fs/foo -c \u0022fpunch 6984k 4k\u0022",
  "published": "2025-10-28T10:15:40Z",
  "severity": "Moderate",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00144,
  "epssPercentile": 0.03711,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40025",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.17.6-1",
      "fix": "DEBIAN-CVE-2025-40025",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-40025",
      "released": "2025-10-28T10:15:40Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}