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.
diff --git a/ChangeLog b/ChangeLog
index 60383a9..8090a70 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -29,6 +29,8 @@
a contribution from Tobias Tangemann. #541
* Fixed cert_app sample program for debug output and for use when no root
certificates are provided.
+ * 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.
diff --git a/library/threading.c b/library/threading.c
index 1b6d9cd..83ec01a 100644
--- a/library/threading.c
+++ b/library/threading.c
@@ -32,7 +32,7 @@
#if defined(MBEDTLS_THREADING_PTHREAD)
static void threading_mutex_init_pthread( mbedtls_threading_mutex_t *mutex )
{
- if( mutex == NULL )
+ if( mutex == NULL || mutex->is_valid )
return;
mutex->is_valid = pthread_mutex_init( &mutex->mutex, NULL ) == 0;
@@ -40,10 +40,11 @@
static void threading_mutex_free_pthread( mbedtls_threading_mutex_t *mutex )
{
- if( mutex == NULL )
+ if( mutex == NULL || !mutex->is_valid )
return;
(void) pthread_mutex_destroy( &mutex->mutex );
+ mutex->is_valid = 0;
}
static int threading_mutex_lock_pthread( mbedtls_threading_mutex_t *mutex )