From fc194354bce7b969bb42907d534d0ccb96d60b87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=2E=20Mert=20Y=C4=B1ld=C4=B1ran?= <mehmet@up9.com>
Date: Tue, 17 May 2022 03:13:50 -0700
Subject: [PATCH] Fix a `nil pointer dereference` error that occurs in
 `tcpReader`'s `Read` method (#1090)

* Fix a `nil pointer dereference` error that occurs in `tcpReader`'s `Read` method

* #run_acceptance_tests

* #run_acceptance_tests

* Revert "Fix a `nil pointer dereference` error that occurs in `tcpReader`'s `Read` method"

This reverts commit ccef6cb3931d0de6f3636e753eb82d045144392d.

* Fix the race condition using locks #run_acceptance_tests
---
 tap/tcp_reader.go | 6 +++++-
 tap/tcp_stream.go | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tap/tcp_reader.go b/tap/tcp_reader.go
index e15ae87db..23528ff59 100644
--- a/tap/tcp_reader.go
+++ b/tap/tcp_reader.go
@@ -82,10 +82,14 @@ func (reader *tcpReader) isProtocolIdentified() bool {
 }
 
 func (reader *tcpReader) rewind() {
-	// Reset the data and msgBuffer from the master record
+	// Reset the data
 	reader.data = make([]byte, 0)
+
+	// Reset msgBuffer from the master record
+	reader.parent.Lock()
 	reader.msgBuffer = make([]api.TcpReaderDataMsg, len(reader.msgBufferMaster))
 	copy(reader.msgBuffer, reader.msgBufferMaster)
+	reader.parent.Unlock()
 
 	// Reset the read progress
 	reader.progress.Reset()
diff --git a/tap/tcp_stream.go b/tap/tcp_stream.go
index ca99da6c6..31664ac3e 100644
--- a/tap/tcp_stream.go
+++ b/tap/tcp_stream.go
@@ -72,8 +72,10 @@ func (t *tcpStream) SetProtocol(protocol *api.Protocol) {
 	t.protocol = protocol
 
 	// Clean the buffers
+	t.Lock()
 	t.client.msgBufferMaster = make([]api.TcpReaderDataMsg, 0)
 	t.server.msgBufferMaster = make([]api.TcpReaderDataMsg, 0)
+	t.Unlock()
 }
 
 func (t *tcpStream) GetOrigin() api.Capture {