diff --git a/libavformat/asfdec.c b/libavformat/asfdec.c
index f2dd489b991c89991c25a30f2f749380122174ba..9989b8073c631b0a93e1ff446e6542109a3ef894 100644
--- a/libavformat/asfdec.c
+++ b/libavformat/asfdec.c
@@ -1591,6 +1591,8 @@ static int detect_unknown_subobject(AVFormatContext *s, int64_t offset, int64_t
     int ret;
 
     while (avio_tell(pb) <= offset + size) {
+        if (avio_tell(pb) == asf->offset)
+            break;
         asf->offset = avio_tell(pb);
         if ((ret = ff_get_guid(pb, &guid)) < 0)
             return ret;