proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftDecoder.java

@@ -104,7 +104,7 @@ public class MinecraftDecoder extends ChannelInboundHandlerAdapter {
       throw handleOverflow(packet, expectedMaxLen, buf.readableBytes());
     }
     if (buf.readableBytes() < expectedMinLen) {
-      throw handleUnderflow(packet, expectedMaxLen, buf.readableBytes());
+      throw handleUnderflow(packet, expectedMinLen, buf.readableBytes());
     }
   }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java

@@ -159,10 +159,10 @@ public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder {
     int expectedMinLen = packet.decodeExpectedMinLength(in, direction, registry.version);
     int expectedMaxLen = packet.decodeExpectedMaxLength(in, direction, registry.version);
     if (expectedMaxLen != -1 && payloadLength > expectedMaxLen) {
-      throw handleOverflow(packet, expectedMaxLen, in.readableBytes());
+      throw handleOverflow(packet, expectedMaxLen, payloadLength);
     }
     if (payloadLength < expectedMinLen) {
-      throw handleUnderflow(packet, expectedMaxLen, in.readableBytes());
+      throw handleUnderflow(packet, expectedMinLen, payloadLength);
     }
 
     in.readerIndex(index);