kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-08 18:57:22 +00:00
Code Issues Releases Packages Activity

fs/ntfs3: add bounds check to run_get_highest_vcn()

Browse source 
run_get_highest_vcn() parses a packed NTFS mapping-pairs buffer without
any length bound, relying solely on a 0x00 terminator to stop.  A
crafted $LogFile UpdateMappingPairs record whose embedded attribute
contains mapping-pairs runs without a terminator causes the function to
read past the slab allocation, triggering a KASAN slab-out-of-bounds
read on mount.

The sibling function run_unpack() received an analogous bounds-check in
commit b62567bca4 ("ntfs3: add buffer boundary checks to run_unpack()"),
but run_get_highest_vcn() was missed.

Take a run_buf_size parameter and reject any run header whose payload
would extend past the buffer end, mirroring the pattern used by
run_unpack().  The caller in fslog.c passes the remaining attribute
bytes after the mapping-pairs offset.

KASAN report (on mainline v7.1 merge window HEAD):

  BUG: KASAN: slab-out-of-bounds in run_get_highest_vcn+0x3c0/0x410
  Read of size 1 at addr ffff88800e2d5400 by task mount/72
  Call Trace:
   run_get_highest_vcn+0x3c0/0x410
   do_action.isra.0+0x3ba8/0x7b50
   log_replay+0x9ddd/0x10200
   ntfs_loadlog_and_replay+0x4ad/0x610
   ntfs_fill_super+0x214a/0x4540

Fixes: b62567bca4 ("ntfs3: add buffer boundary checks to run_unpack()")
Signed-off-by: Jaeyeong Lee <lee@jaeyeong.cc>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
This commit is contained in:
Konstantin Komarov 2026-04-30 14:30:13 +02:00
commit bb11485a87
No known key found for this signature in database
GPG key ID: A9B0331F832407B6
3 changed files with 13 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files