diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
index aaaa0d3d..12d8682 100644
--- a/fs/ntfs3/run.c
+++ b/fs/ntfs3/run.c
@@ -919,12 +919,15 @@ int run_pack(const struct runs_tree *run, CLST svcn, CLST len, u8 *run_buf,
  */
 int run_unpack(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
 	       CLST svcn, CLST evcn, CLST vcn, const u8 *run_buf,
-	       u32 run_buf_size)
+	       int run_buf_size)
 {
 	u64 prev_lcn, vcn64, lcn, next_vcn;
 	const u8 *run_last, *run_0;
 	bool is_mft = ino == MFT_REC_MFT;
 
+	if (run_buf_size < 0)
+		return -EINVAL;
+
 	/* Check for empty. */
 	if (evcn + 1 == svcn)
 		return 0;
@@ -1046,7 +1049,7 @@ int run_unpack(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
  */
 int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
 		  CLST svcn, CLST evcn, CLST vcn, const u8 *run_buf,
-		  u32 run_buf_size)
+		  int run_buf_size)
 {
 	int ret, err;
 	CLST next_vcn, lcn, len;