large mp4 header handling

components/squeezelite/helix-aac.c

@@ -314,9 +314,15 @@ static int read_mp4_header(unsigned long *samplerate_p, unsigned char *channels_
 			a->pos += bytes;
 			a->consume = consume - bytes;
 			break;
-		} else {
+		} else if (len > streambuf->size) {
+ 			// can't process an atom larger than streambuf!
+			LOG_ERROR("atom %s too large for buffer %u %u", type, len, streambuf->size);
+			return -1;
+		 } else {
+			 // make sure there is 'len' contiguous space
+			_buf_unwrap(streambuf, len); 
 			break;
-		}
+		 }
 	}
 
 	return 0;