From b48c8ac45d84bb9871677a1dd28f5160bfb5737f Mon Sep 17 00:00:00 2001
From: Janos Follath <janos.follath@arm.com>
Date: Mon, 26 Sep 2016 09:15:44 +0100
Subject: [PATCH] Add safety check to sample mutex implementation

Due to inconsistent freeing strategy in pkparse.c the sample mutex
implementation in threading.c could lead to undefined behaviour by
destroying the same mutex several times.

This fix prevents mutexes from being destroyed several times in the
sample threading implementation.
---
 ChangeLog | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 0412613b0..47dfae6b6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,6 +42,8 @@ Bugfix
    * Fixed the sample applications gen_key.c, cert_req.c and cert_write.c for
      builds where the configuration MBEDTLS_PEM_WRITE_C is not defined. Found
      by inestlerode. #559.
+   * Fixed default threading implementation to avoid accidental double
+     initialisations and double frees.
 
 Changes
    * Extended test coverage of special cases, and added new timing test suite.