fkie_cve-2025-40025
Vulnerability from fkie_nvd
Published
2025-10-28 10:15
Modified
2025-10-30 15:05
Severity ?
Summary
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+0x69e/0x6c0 fs/f2fs/file.c:1243 Call Trace: <TASK> f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306 f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018 vfs_fallocate+0x666/0x7e0 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+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 || ...). count = 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 "fpunch 6984k 4k"
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/186098f34b8a5d65eb828f952c8cc56272c60ea0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c18ecd99e0c707ef8f83cace861cbc3162f4fdf1
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on node footer for non inode dnode\n\nAs syzbot reported below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/file.c:1243!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nCPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full)\nRIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243\nCall Trace:\n \u003cTASK\u003e\n f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306\n f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018\n vfs_fallocate+0x666/0x7e0 fs/open.c:342\n ksys_fallocate fs/open.c:366 [inline]\n __do_sys_fallocate fs/open.c:371 [inline]\n __se_sys_fallocate fs/open.c:369 [inline]\n __x64_sys_fallocate+0xc0/0x110 fs/open.c:369\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f1e65f8ebe9\n\nw/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent\ntruncation range in direct node in f2fs_truncate_hole().\n\nThe root cause is: a non-inode dnode may has the same footer.ino and\nfooter.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE()\nmay return wrong blkaddr count which may be 923 typically, by chance,\ndn.ofs_in_node is equal to 923, then count can be calculated to 0 in below\nstatement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...).\n\n\tcount = min(end_offset - dn.ofs_in_node, pg_end - pg_start);\n\nThis patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing\npassing the new_type to sanity_check_node_footer in f2fs_get_node_folio()\nto detect corruption that a non-inode dnode has the same footer.ino and\nfooter.nid.\n\nScripts to reproduce:\nmkfs.f2fs -f /dev/vdb\nmount /dev/vdb /mnt/f2fs\ntouch /mnt/f2fs/foo\ntouch /mnt/f2fs/bar\ndd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8\numount /mnt/f2fs\ninject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb\nmount /dev/vdb /mnt/f2fs\nxfs_io /mnt/f2fs/foo -c \"fpunch 6984k 4k\""
    }
  ],
  "id": "CVE-2025-40025",
  "lastModified": "2025-10-30T15:05:32.197",
  "metrics": {},
  "published": "2025-10-28T10:15:40.920",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/186098f34b8a5d65eb828f952c8cc56272c60ea0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c18ecd99e0c707ef8f83cace861cbc3162f4fdf1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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