From d6ec44c871e8598a62a2a403949fbc28d52898bc Mon Sep 17 00:00:00 2001
From: Norman Maurer <nmaurer@redhat.com>
Date: Fri, 18 Apr 2014 20:34:37 +0200
Subject: [PATCH] Fix buffer leak in EpollDatagramChannel

Motivation:
EpollDatagramChannel produced buffer leaks when tried to read from the channel and nothing was ready to be read.

Modifications:
Correctly release buffer if nothing was read

Result:
No buffer leak
---
 .../channel/epoll/EpollDatagramChannel.java   | 40 +++++++------------
 1 file changed, 15 insertions(+), 25 deletions(-)

diff --git a/transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java b/transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java
index 9774d816d4..d7cb9f1cb9 100644
--- a/transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java
+++ b/transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java
@@ -376,12 +376,11 @@ public final class EpollDatagramChannel extends AbstractEpollChannel implements
 
             assert eventLoop().inEventLoop();
             final ChannelPipeline pipeline = pipeline();
-            Throwable exception = null;
             try {
-                try {
-                    for (;;) {
-                        boolean free = true;
-                        ByteBuf data = allocHandle.allocate(config.getAllocator());
+                for (;;) {
+                    ByteBuf data = null;
+                    try {
+                        data = allocHandle.allocate(config.getAllocator());
                         int writerIndex = data.writerIndex();
                         DatagramSocketAddress remoteAddress;
                         if (data.hasMemoryAddress()) {
@@ -401,28 +400,19 @@ public final class EpollDatagramChannel extends AbstractEpollChannel implements
                         int readBytes = remoteAddress.receivedAmount;
                         data.writerIndex(data.writerIndex() + readBytes);
                         allocHandle.record(readBytes);
-                        try {
-                            readPending = false;
-                            pipeline.fireChannelRead(
-                                    new DatagramPacket(data, (InetSocketAddress) localAddress(), remoteAddress));
-                            free = false;
-                        } catch (Throwable t) {
-                            // keep on reading as we use epoll ET and need to consume everything from the socket
-                            pipeline.fireChannelReadComplete();
-                            pipeline.fireExceptionCaught(t);
-                        } finally {
-                            if (free) {
-                                data.release();
-                            }
+                        readPending = false;
+                        pipeline.fireChannelRead(
+                                new DatagramPacket(data, (InetSocketAddress) localAddress(), remoteAddress));
+                        data = null;
+                    } catch (Throwable t) {
+                        // keep on reading as we use epoll ET and need to consume everything from the socket
+                        pipeline.fireChannelReadComplete();
+                        pipeline.fireExceptionCaught(t);
+                    } finally {
+                        if (data != null) {
+                            data.release();
                         }
                     }
-                } catch (Throwable t) {
-                    exception = t;
-                }
-                pipeline.fireChannelReadComplete();
-
-                if (exception != null) {
-                    pipeline.fireExceptionCaught(exception);
                 }
             } finally {
                 // Check if there is a readPending which was not processed yet.