[pre-commit.ci lite] apply automatic fixes

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

esphome/components/modbus_controller/modbus_controller.h

@@ -285,8 +285,13 @@ class ServerRegister {
       case SensorValueType::S_QWORD_R:
         return std::to_string(value);
       case SensorValueType::FP32_R:
-      case SensorValueType::FP32:
-        return str_sprintf("%.1f", bit_cast<float>(static_cast<uint32_t>(value)));
+      case SensorValueType::FP32: {
+        // max 48: float with %.1f can be up to 42 chars incl. null (3.4e38 → 38 integer digits + decimal point + 1
+        // decimal digit + optional sign)
+        char buf[48];
+        snprintf(buf, sizeof(buf), "%.1f", bit_cast<float>(static_cast<uint32_t>(value)));
+        return buf;
+      }
       default:
         return std::to_string(value);
     }

esphome/components/modbus_controller/text_sensor/modbus_textsensor.cpp

@@ -16,12 +16,20 @@ void ModbusTextSensor::parse_and_publish(const std::vector<uint8_t> &data) {
   while ((items_left > 0) && index < data.size()) {
     uint8_t b = data[index];
     switch (this->encode_) {
-      case RawEncoding::HEXBYTES:
-        output_str += str_snprintf("%02x", 2, b);
+      case RawEncoding::HEXBYTES: {
+        // max 3: 2 hex digits + null
+        char hex_buf[3];
+        snprintf(hex_buf, sizeof(hex_buf), "%02x", b);
+        output_str += hex_buf;
         break;
-      case RawEncoding::COMMA:
-        output_str += str_sprintf(index != this->offset ? ",%d" : "%d", b);
+      }
+      case RawEncoding::COMMA: {
+        // max 5: optional ','(1) + uint8(3) + null, for both ",%d" and "%d"
+        char dec_buf[5];
+        snprintf(dec_buf, sizeof(dec_buf), index != this->offset ? ",%d" : "%d", b);
+        output_str += dec_buf;
         break;
+      }
       case RawEncoding::ANSI:
         if (b < 0x20)
           break;

esphome/components/mqtt/mqtt_client.cpp

@@ -91,15 +91,7 @@ void MQTTClientComponent::send_device_info_() {
         uint8_t index = 0;
         for (auto &ip : network::get_ip_addresses()) {
           if (ip.is_set()) {
-            char key[8];  // "ip" + up to 3 digits + null
-            char ip_buf[network::IP_ADDRESS_BUFFER_SIZE];
-            if (index == 0) {
-              strcpy(key, "ip");
-            } else {
-              snprintf(key, sizeof(key), "ip%u", index);
-            }
-            ip.str_to(ip_buf);
-            root[key] = ip_buf;
+            root["ip" + (index == 0 ? "" : esphome::to_string(index))] = ip.str();
             index++;
           }
         }

esphome/components/mqtt/mqtt_component.cpp

@@ -232,11 +232,7 @@ bool MQTTComponent::send_discovery_() {
 #else
         const char *fmt = ver_fmt;
 #endif
-        // Buffer sized for format string expansion: ~4 bytes net growth from format specifier to 8 hex digits, plus
-        // safety margin
-        char version_buf[sizeof(ver_fmt) + 8];
-        snprintf(version_buf, sizeof(version_buf), fmt, App.get_config_hash());
-        device_info[MQTT_DEVICE_SW_VERSION] = version_buf;
+        device_info[MQTT_DEVICE_SW_VERSION] = str_sprintf(fmt, App.get_config_hash());
         device_info[MQTT_DEVICE_MODEL] = ESPHOME_BOARD;
 #if defined(USE_ESP8266) || defined(USE_ESP32)
         device_info[MQTT_DEVICE_MANUFACTURER] = "Espressif";