parallels: Check if data_end greater than the file size

Initially data_end is set to the data_off image header field and must not
be greater than the file size.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>

block/parallels.c

@@ -874,6 +874,11 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
          */
         s->header_size = size;
     }
+    if (s->data_end > file_nb_sectors) {
+        error_setg(errp, "Invalid image: incorrect data_off field");
+        ret = -EINVAL;
+        goto fail;
+    }
 
     ret = bdrv_pread(bs->file, 0, s->header_size, s->header, 0);
     if (ret < 0) {