Make sure host_metrics user_string is null terminated

jp-bennett · jp-bennett · commit 3ab9005b2f20 · 2025-06-17T11:11:36.000-05:00
diff --git a/src/modules/Telemetry/HostMetrics.cpp b/src/modules/Telemetry/HostMetrics.cpp
@@ -111,7 +111,8 @@ meshtastic_Telemetry HostMetricsModule::getHostMetrics()
     if (settingsStrings[hostMetrics_user_command] != "") {
         std::string userCommandResult = exec(settingsStrings[hostMetrics_user_command].c_str());
         if (userCommandResult.length() > 1) {
-            strncpy(t.variant.host_metrics.user_string, userCommandResult.c_str(), 200);
+            strncpy(t.variant.host_metrics.user_string, userCommandResult.c_str(), sizeof(t.variant.host_metrics.user_string));
+            t.variant.host_metrics.user_string[ sizeof(t.variant.host_metrics.user_string) - 1] = '\0';
             t.variant.host_metrics.has_user_string = true;
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -111,7 +111,8 @@ meshtastic_Telemetry HostMetricsModule::getHostMetrics()`
`111`	`111`	`if (settingsStrings[hostMetrics_user_command] != "") {`
`112`	`112`	`std::string userCommandResult = exec(settingsStrings[hostMetrics_user_command].c_str());`
`113`	`113`	`if (userCommandResult.length() > 1) {`
`114`		`- strncpy(t.variant.host_metrics.user_string, userCommandResult.c_str(), 200);`
	`114`	`+ strncpy(t.variant.host_metrics.user_string, userCommandResult.c_str(), sizeof(t.variant.host_metrics.user_string));`
	`115`	`+ t.variant.host_metrics.user_string[ sizeof(t.variant.host_metrics.user_string) - 1] = '\0';`
`115`	`116`	`t.variant.host_metrics.has_user_string = true;`
`116`	`117`	`}`
`117`	`118`	`}`