diff --git a/src/modules/navigator/mission.cpp b/src/modules/navigator/mission.cpp
index 4f1a6e2bb2..d92af2427a 100644
--- a/src/modules/navigator/mission.cpp
+++ b/src/modules/navigator/mission.cpp
@@ -1942,113 +1942,143 @@ void Mission::calculate_mission_checksums()
 	csum.rally_checksum = 0;
 	csum.all_checksum = 0;
 
+	bool fail = false;
+
 	dm_lock(DM_KEY_MISSION_STATE);
 
 	if (dm_read(DM_KEY_MISSION_STATE, 0, &mission_state, sizeof(mission_s)) != sizeof(mission_s)) {
 		PX4_ERR("dataman read failure");
-		return;
+		fail = true;
 	}
 
 	dm_unlock(DM_KEY_MISSION_STATE);
 
-	dm_item_t dm_current = (dm_item_t)(_mission.dataman_id);
+	if (fail) {
+		return;
+	}
 
-	for (int i = 0; i < mission_state.count; i++) {
+	dm_item_t dm_current = (dm_item_t)(_mission.dataman_id);
+	dm_lock(dm_current);
+
+	for (int i = 0; i < mission_state.count && !fail; i++) {
 		struct mission_item_s mission_item = {};
 		const ssize_t len = sizeof(mission_item);
 
 		if (dm_read(dm_current, i, &mission_item, len) != len) {
 			PX4_ERR("dataman read failure");
-			return;
-		}
+			fail = true;
 
-		uint8_t frame = mission_item.frame;
-		csum.mission_checksum = crc32part(&frame, sizeof(frame), csum.mission_checksum);
-		csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_item.nav_cmd), sizeof(mission_item.nav_cmd),
-						  csum.mission_checksum);
-		uint8_t autocontinue = mission_item.autocontinue;
-		csum.mission_checksum = crc32part(&autocontinue, sizeof(autocontinue), csum.mission_checksum);
-
-		for (int j = 0; j < 4; j++) {
-			csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_item.params[j]), sizeof(mission_item.params[j]),
+		} else {
+			uint8_t frame = mission_item.frame;
+			csum.mission_checksum = crc32part(&frame, sizeof(frame), csum.mission_checksum);
+			csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_item.nav_cmd), sizeof(mission_item.nav_cmd),
 							  csum.mission_checksum);
-		}
+			uint8_t autocontinue = mission_item.autocontinue;
+			csum.mission_checksum = crc32part(&autocontinue, sizeof(autocontinue), csum.mission_checksum);
 
-		float lat = static_cast<float>(mission_item.lat);
-		csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.mission_checksum);
-		float lon = static_cast<float>(mission_item.lon);
-		csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.mission_checksum);
-		float alt = mission_item.params[6];
-		csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&alt), sizeof(alt), csum.mission_checksum);
+			for (int j = 0; j < 4; j++) {
+				csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_item.params[j]), sizeof(mission_item.params[j]),
+								  csum.mission_checksum);
+			}
+
+			float lat = static_cast<float>(mission_item.lat);
+			csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.mission_checksum);
+			float lon = static_cast<float>(mission_item.lon);
+			csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.mission_checksum);
+			float alt = mission_item.params[6];
+			csum.mission_checksum = crc32part(reinterpret_cast<uint8_t *>(&alt), sizeof(alt), csum.mission_checksum);
+		}
+	}
+
+	dm_unlock(dm_current);
+
+	if (fail) {
+		return;
 	}
 
 	csum.all_checksum = csum.mission_checksum;
 
+	dm_lock(DM_KEY_FENCE_POINTS);
+
 	if (dm_read(DM_KEY_FENCE_POINTS, 0, &stats, sizeof(mission_stats_entry_s)) != sizeof(mission_stats_entry_s)) {
 		PX4_ERR("dataman read failure");
-		return;
+		fail = true;
 	}
 
-	for (size_t i = 1; i <= stats.num_items; i++) {
+	for (size_t i = 1; i <= stats.num_items && !fail; i++) {
 		mission_fence_point_s mission_fence_point;
 		const ssize_t len = sizeof(mission_fence_point);
 
 		if (dm_read(DM_KEY_FENCE_POINTS, i, &mission_fence_point, len) != len) {
 			PX4_ERR("dataman read failure");
-			return;
-		}
+			fail = true;
 
-		uint8_t frame = mission_fence_point.frame;
-		csum.fence_checksum = crc32part(&frame, sizeof(frame), csum.fence_checksum);
-		csum.all_checksum = crc32part(&frame, sizeof(frame), csum.all_checksum);
-		csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.nav_cmd),
-						sizeof(mission_fence_point.nav_cmd), csum.fence_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.nav_cmd),
-					      sizeof(mission_fence_point.nav_cmd), csum.all_checksum);
-		float lat = static_cast<float>(mission_fence_point.lat);
-		csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.fence_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.all_checksum);
-		float lon = static_cast<float>(mission_fence_point.lon);
-		csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.fence_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.all_checksum);
-		csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.alt), sizeof(mission_fence_point.alt),
-						csum.fence_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.alt), sizeof(mission_fence_point.alt),
-					      csum.all_checksum);
-		csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.circle_radius),
-						sizeof(mission_fence_point.circle_radius), csum.fence_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.circle_radius),
-					      sizeof(mission_fence_point.circle_radius), csum.all_checksum);
+		} else {
+			uint8_t frame = mission_fence_point.frame;
+			csum.fence_checksum = crc32part(&frame, sizeof(frame), csum.fence_checksum);
+			csum.all_checksum = crc32part(&frame, sizeof(frame), csum.all_checksum);
+			csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.nav_cmd),
+							sizeof(mission_fence_point.nav_cmd), csum.fence_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.nav_cmd),
+						      sizeof(mission_fence_point.nav_cmd), csum.all_checksum);
+			float lat = static_cast<float>(mission_fence_point.lat);
+			csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.fence_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.all_checksum);
+			float lon = static_cast<float>(mission_fence_point.lon);
+			csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.fence_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.all_checksum);
+			csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.alt), sizeof(mission_fence_point.alt),
+							csum.fence_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.alt), sizeof(mission_fence_point.alt),
+						      csum.all_checksum);
+			csum.fence_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.circle_radius),
+							sizeof(mission_fence_point.circle_radius), csum.fence_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_fence_point.circle_radius),
+						      sizeof(mission_fence_point.circle_radius), csum.all_checksum);
+		}
 	}
 
-	if (dm_read(DM_KEY_SAFE_POINTS, 0, &stats, sizeof(mission_stats_entry_s)) != sizeof(mission_stats_entry_s)) {
-		PX4_ERR("dataman read failure");
+	dm_unlock(DM_KEY_FENCE_POINTS);
+
+	if (fail) {
 		return;
 	}
 
-	for (size_t i = 1; i <= stats.num_items; i++) {
+	dm_lock(DM_KEY_SAFE_POINTS);
+
+	if (dm_read(DM_KEY_SAFE_POINTS, 0, &stats, sizeof(mission_stats_entry_s)) != sizeof(mission_stats_entry_s)) {
+		PX4_ERR("dataman read failure");
+		fail = true;
+	}
+
+	for (size_t i = 1; i <= stats.num_items && !fail; i++) {
 		mission_safe_point_s mission_safe_point;
 		const ssize_t len = sizeof(mission_safe_point);
 
 		if (dm_read(DM_KEY_SAFE_POINTS, i, &mission_safe_point, len) != len) {
 			PX4_ERR("dataman read failure");
-			return;
-		}
+			fail = true;
 
-		uint8_t frame = mission_safe_point.frame;
-		csum.rally_checksum = crc32part(&frame, sizeof(frame), csum.rally_checksum);
-		csum.all_checksum = crc32part(&frame, sizeof(frame), csum.all_checksum);
-		float lat = static_cast<float>(mission_safe_point.lat);
-		csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.rally_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.all_checksum);
-		float lon = static_cast<float>(mission_safe_point.lon);
-		csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.rally_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.all_checksum);
-		csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_safe_point.alt), sizeof(mission_safe_point.alt),
-						csum.rally_checksum);
-		csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_safe_point.alt), sizeof(mission_safe_point.alt),
-					      csum.all_checksum);
+		} else {
+			uint8_t frame = mission_safe_point.frame;
+			csum.rally_checksum = crc32part(&frame, sizeof(frame), csum.rally_checksum);
+			csum.all_checksum = crc32part(&frame, sizeof(frame), csum.all_checksum);
+			float lat = static_cast<float>(mission_safe_point.lat);
+			csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.rally_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lat), sizeof(lat), csum.all_checksum);
+			float lon = static_cast<float>(mission_safe_point.lon);
+			csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.rally_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&lon), sizeof(lon), csum.all_checksum);
+			csum.rally_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_safe_point.alt), sizeof(mission_safe_point.alt),
+							csum.rally_checksum);
+			csum.all_checksum = crc32part(reinterpret_cast<uint8_t *>(&mission_safe_point.alt), sizeof(mission_safe_point.alt),
+						      csum.all_checksum);
+		}
 	}
 
-	mission_checksum_pub.publish(csum);
-}
\ No newline at end of file
+	dm_unlock(DM_KEY_SAFE_POINTS);
+
+	if (!fail) {
+		mission_checksum_pub.publish(csum);
+	}
+}