From 51bb4be6c448a1ba6c9647f10359f4d5268ec91a Mon Sep 17 00:00:00 2001
From: kangping <wgtdkp@google.com>
Date: Thu, 23 Jan 2020 02:05:22 +0800
Subject: [PATCH] [meshcop] fix premature free of finalize message (#4487)

This commit fixes a bug that the finalize message will be prematurely
freed if the joiner is started at the second time without waiting for
the finish of the first initiation.
---
 src/core/meshcop/joiner.cpp | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/core/meshcop/joiner.cpp b/src/core/meshcop/joiner.cpp
index f94ad7933..0f623003a 100644
--- a/src/core/meshcop/joiner.cpp
+++ b/src/core/meshcop/joiner.cpp
@@ -163,11 +163,11 @@ void Joiner::Finish(otError aError)
 
     case OT_JOINER_STATE_DISCOVER:
         Get<Coap::CoapSecure>().Stop();
-        FreeJoinerFinalizeMessage();
         break;
     }
 
     SetState(OT_JOINER_STATE_IDLE);
+    FreeJoinerFinalizeMessage();
 
     if (mCallback)
     {
@@ -450,11 +450,13 @@ exit:
 
 void Joiner::FreeJoinerFinalizeMessage(void)
 {
-    if (mFinalizeMessage != NULL)
-    {
-        mFinalizeMessage->Free();
-        mFinalizeMessage = NULL;
-    }
+    VerifyOrExit(mState == OT_JOINER_STATE_IDLE && mFinalizeMessage != NULL);
+
+    mFinalizeMessage->Free();
+    mFinalizeMessage = NULL;
+
+exit:
+    return;
 }
 
 void Joiner::SendJoinerFinalize(void)