diff --git a/sys/vfs/ntfs/ntfs_subr.c b/sys/vfs/ntfs/ntfs_subr.c
--- a/sys/vfs/ntfs/ntfs_subr.c
+++ b/sys/vfs/ntfs/ntfs_subr.c
@@ -885,7 +885,7 @@
 
 	dprintf(("ntfs_ntlookupfile: blksz: %d, rdsz: %d\n", blsize, rdsize));
 
-	rdbuf = kmalloc(blsize, M_TEMP, M_WAITOK);
+	rdbuf = kmalloc(max(blsize, rdsize), M_TEMP, M_WAITOK);
 
 	error = ntfs_readattr(ntmp, ip, NTFS_A_INDXROOT, "$I30",
 			       0, rdsize, rdbuf, NULL);