Bugfix: Prevent access to iterator when block/unblock is called by an unregistered thread. (#15)

aentinger · web-flow · commit 0faf9abb0958 · 2021-09-06T08:48:25.000+02:00
diff --git a/src/serial/SerialDispatcher.cpp b/src/serial/SerialDispatcher.cpp
@@ -153,13 +153,15 @@ void SerialDispatcher::block()
 {
   mbed::ScopedLock<rtos::Mutex> lock(_mutex);
   auto iter = findThreadCustomerDataById(rtos::ThisThread::get_id());
+  if (iter == std::end(_thread_customer_list)) return;
   iter->block_tx_buffer = true;
 }
 
 void SerialDispatcher::unblock()
 {
   mbed::ScopedLock<rtos::Mutex> lock(_mutex);
   auto iter = findThreadCustomerDataById(rtos::ThisThread::get_id());
+  if (iter == std::end(_thread_customer_list)) return;
   iter->block_tx_buffer = false;
   _cond.notify_one();
 }

Original file line number	Diff line number	Diff line change
`@@ -153,13 +153,15 @@ void SerialDispatcher::block()`
`153`	`153`	`{`
`154`	`154`	`mbed::ScopedLock<rtos::Mutex> lock(_mutex);`
`155`	`155`	`auto iter = findThreadCustomerDataById(rtos::ThisThread::get_id());`
	`156`	`+ if (iter == std::end(_thread_customer_list)) return;`
`156`	`157`	`iter->block_tx_buffer = true;`
`157`	`158`	`}`
`158`	`159`
`159`	`160`	`void SerialDispatcher::unblock()`
`160`	`161`	`{`
`161`	`162`	`mbed::ScopedLock<rtos::Mutex> lock(_mutex);`
`162`	`163`	`auto iter = findThreadCustomerDataById(rtos::ThisThread::get_id());`
	`164`	`+ if (iter == std::end(_thread_customer_list)) return;`
`163`	`165`	`iter->block_tx_buffer = false;`
`164`	`166`	`_cond.notify_one();`
`165`	`167`	`}`