diff --git a/libraries/AP_HAL_Linux/CANSocketIface.cpp b/libraries/AP_HAL_Linux/CANSocketIface.cpp
index 5d35fe7115..c2203afa39 100644
--- a/libraries/AP_HAL_Linux/CANSocketIface.cpp
+++ b/libraries/AP_HAL_Linux/CANSocketIface.cpp
@@ -167,17 +167,19 @@ int16_t CANIface::send(const AP_HAL::CANFrame& frame, const uint64_t tx_deadline
     tx_item.setup = true;
     tx_item.index = _tx_frame_counter;
     tx_item.deadline = tx_deadline;
+    WITH_SEMAPHORE(sem);
     _tx_queue.emplace(tx_item);
     _tx_frame_counter++;
     stats.tx_requests++;
     _pollRead();     // Read poll is necessary because it can release the pending TX flag
     _pollWrite();
-    return 1;
+    return AP_HAL::CANIface::send(frame, tx_deadline, flags);
 }
 
 int16_t CANIface::receive(AP_HAL::CANFrame& out_frame, uint64_t& out_timestamp_us,
                           CANIface::CanIOFlags& out_flags)
 {
+    WITH_SEMAPHORE(sem);
     if (_rx_queue.empty()) {
         _pollRead();            // This allows to use the socket not calling poll() explicitly.
         if (_rx_queue.empty()) {
@@ -191,16 +193,18 @@ int16_t CANIface::receive(AP_HAL::CANFrame& out_frame, uint64_t& out_timestamp_u
         out_flags        = rx.flags;
     }
     (void)_rx_queue.pop();
-    return 1;
+    return AP_HAL::CANIface::receive(out_frame, out_timestamp_us, out_flags);
 }
 
-bool CANIface::_hasReadyTx() const
+bool CANIface::_hasReadyTx()
 {
+    WITH_SEMAPHORE(sem);
     return !_tx_queue.empty() && (_frames_in_socket_tx_queue < _max_frames_in_socket_tx_queue);
 }
 
-bool CANIface::_hasReadyRx() const
+bool CANIface::_hasReadyRx()
 {
+    WITH_SEMAPHORE(sem);
     return !_rx_queue.empty();
 }
 
@@ -263,6 +267,7 @@ uint32_t CANIface::getErrorCount() const
 void CANIface::_pollWrite()
 {
     while (_hasReadyTx()) {
+        WITH_SEMAPHORE(sem);
         const CanTxItem tx = _tx_queue.top();
         uint64_t curr_time = AP_HAL::native_micros64();
         if (tx.deadline >= curr_time) {
@@ -309,6 +314,7 @@ bool CANIface::_pollRead()
                 stats.tx_confirmed++;
             }
             if (accept) {
+                WITH_SEMAPHORE(sem);
                 _rx_queue.push(rx);
                 stats.rx_received++;
                 return true;
@@ -390,6 +396,7 @@ int CANIface::_read(AP_HAL::CANFrame& frame, uint64_t& timestamp_us, bool& loopb
 // Might block forever, only to be used for testing
 void CANIface::flush_tx()
 {
+    WITH_SEMAPHORE(sem);
     do {
         _updateDownStatusFromPollResult(_pollfd);
         _poll(true, true);
@@ -398,6 +405,7 @@ void CANIface::flush_tx()
 
 void CANIface::clear_rx()
 {
+    WITH_SEMAPHORE(sem);
     // Clean Rx Queue
     std::queue<CanRxItem> empty;
     std::swap( _rx_queue, empty );
diff --git a/libraries/AP_HAL_Linux/CANSocketIface.h b/libraries/AP_HAL_Linux/CANSocketIface.h
index edd07410cb..55105c6389 100644
--- a/libraries/AP_HAL_Linux/CANSocketIface.h
+++ b/libraries/AP_HAL_Linux/CANSocketIface.h
@@ -142,9 +142,9 @@ private:
 
     bool _checkHWFilters(const can_frame& frame) const;
 
-    bool _hasReadyTx() const;
+    bool _hasReadyTx();
 
-    bool _hasReadyRx() const;
+    bool _hasReadyRx();
 
     void _poll(bool read, bool write);
 
@@ -190,6 +190,17 @@ private:
         uint32_t num_poll_tx_events;
         uint32_t num_poll_rx_events;
     } stats;
+
+protected:
+    bool add_to_rx_queue(const CanRxItem &rx_item) override {
+        _rx_queue.push(rx_item);
+        return true;
+    }
+
+    int8_t get_iface_num(void) const override {
+        return _self_index;
+    }
+    HAL_Semaphore sem;
 };
 
 }