From: Tobias Gaertner <tob.gaertner@me.com>
The volume boundary check `lcn + len > sbi->used.bitmap.nbits` uses raw
addition which can wrap around for large lcn and len values, bypassing
the validation. Use check_add_overflow() as is already done for the
adjacent prev_lcn + dlcn and vcn64 + len checks added by commit
3ac37e100385 ("ntfs3: Fix integer overflow in run_unpack()").
Found by fuzzing with a source-patched harness (LibAFL + QEMU).
Fixes: 82cae269cfa95 ("fs/ntfs3: Add initialization of super block")
Cc: stable@vger.kernel.org
Signed-off-by: Tobias Gaertner <tob.gaertner@me.com>
---
fs/ntfs3/run.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
index c3c6917fa..a68000bd4 100644
--- a/fs/ntfs3/run.c
+++ b/fs/ntfs3/run.c
@@ -1027,9 +1027,15 @@ int run_unpack(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
return -EOPNOTSUPP;
}
#endif
- if (lcn != SPARSE_LCN64 && lcn + len > sbi->used.bitmap.nbits) {
- /* LCN range is out of volume. */
- return -EINVAL;
+ if (lcn != SPARSE_LCN64) {
+ u64 lcn_end;
+
+ if (check_add_overflow(lcn, len, &lcn_end))
+ return -EINVAL;
+ if (lcn_end > sbi->used.bitmap.nbits) {
+ /* LCN range is out of volume. */
+ return -EINVAL;
+ }
}
if (!run)
--
2.43.0