[multiple] Fix undefined behavior across components (#14639)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

esphome/components/e131/e131_packet.cpp

@@ -1,3 +1,4 @@
+#include <cstddef>
 #include <cstring>
 #include "e131.h"
 #ifdef USE_NETWORK
@@ -57,7 +58,7 @@ union E131RawPacket {
 
 // We need to have at least one `1` value
 // Get the offset of `property_values[1]`
-const size_t E131_MIN_PACKET_SIZE = reinterpret_cast<size_t>(&((E131RawPacket *) nullptr)->property_values[1]);
+const size_t E131_MIN_PACKET_SIZE = offsetof(E131RawPacket, property_values) + sizeof(uint8_t);
 
 bool E131Component::join_igmp_groups_() {
   if (this->listen_method_ != E131_MULTICAST)

esphome/components/globals/globals_component.h

@@ -84,7 +84,7 @@ template<typename T, uint8_t SZ> class RestoringGlobalStringComponent : public P
     this->rtc_ = global_preferences->make_preference<uint8_t[SZ]>(1944399030U ^ this->name_hash_);
     bool hasdata = this->rtc_.load(&temp);
     if (hasdata) {
-      this->value_.assign(temp + 1, temp[0]);
+      this->value_.assign(temp + 1, static_cast<uint8_t>(temp[0]));
     }
     this->last_checked_value_.assign(this->value_);
   }

esphome/components/grove_tb6612fng/grove_tb6612fng.cpp

@@ -139,7 +139,8 @@ void GroveMotorDriveTB6612FNG::stepper_run(StepperModeTypeT mode, int16_t steps,
 }
 
 void GroveMotorDriveTB6612FNG::stepper_stop() {
-  if (this->write_register(GROVE_MOTOR_DRIVER_I2C_CMD_STEPPER_STOP, nullptr, 1) != i2c::ERROR_OK) {
+  uint8_t status = 0;
+  if (this->write_register(GROVE_MOTOR_DRIVER_I2C_CMD_STEPPER_STOP, &status, 1) != i2c::ERROR_OK) {
     ESP_LOGW(TAG, "Send stop stepper failed!");
     this->status_set_warning();
     return;

esphome/components/midea/appliance_base.h

@@ -28,12 +28,14 @@ class UARTStream : public Stream {
   int available() override { return this->uart_->available(); }
   int read() override {
     uint8_t data;
-    this->uart_->read_byte(&data);
+    if (!this->uart_->read_byte(&data))
+      return -1;
     return data;
   }
   int peek() override {
     uint8_t data;
-    this->uart_->peek_byte(&data);
+    if (!this->uart_->peek_byte(&data))
+      return -1;
     return data;
   }
   size_t write(uint8_t data) override {

esphome/components/nextion/nextion.cpp

@@ -651,11 +651,7 @@ void Nextion::process_nextion_commands_() {
           break;
         }
 
-        int value = 0;
-
-        for (int i = 0; i < 4; ++i) {
-          value += to_process[i] << (8 * i);
-        }
+        int value = static_cast<int>(encode_uint32(to_process[3], to_process[2], to_process[1], to_process[0]));
 
         NextionQueue *nb = this->nextion_queue_.front();
         if (!nb || !nb->component) {
@@ -751,10 +747,8 @@ void Nextion::process_nextion_commands_() {
         index = to_process.find('\0');
         variable_name = to_process.substr(0, index);
         // // Get variable name
-        int value = 0;
-        for (int i = 0; i < 4; ++i) {
-          value += to_process[i + index + 1] << (8 * i);
-        }
+        int value = static_cast<int>(
+            encode_uint32(to_process[index + 4], to_process[index + 3], to_process[index + 2], to_process[index + 1]));
 
         ESP_LOGN(TAG, "Sensor: %s=%d", variable_name.c_str(), value);
 

esphome/components/ruuvi_ble/ruuvi_ble.cpp

@@ -21,11 +21,11 @@ bool parse_ruuvi_data_byte(const esp32_ble_tracker::adv_data_t &adv_data, RuuviP
       const float temperature = temp_sign == 0 ? temp_val : -1 * temp_val;
 
       const float humidity = data[0] * 0.5f;
-      const float pressure = (uint16_t(data[3] << 8) + uint16_t(data[4]) + 50000.0f) / 100.0f;
-      const float acceleration_x = (int16_t(data[5] << 8) + int16_t(data[6])) / 1000.0f;
-      const float acceleration_y = (int16_t(data[7] << 8) + int16_t(data[8])) / 1000.0f;
-      const float acceleration_z = (int16_t(data[9] << 8) + int16_t(data[10])) / 1000.0f;
-      const float battery_voltage = (uint16_t(data[11] << 8) + uint16_t(data[12])) / 1000.0f;
+      const float pressure = (encode_uint16(data[3], data[4]) + 50000.0f) / 100.0f;
+      const float acceleration_x = static_cast<int16_t>(encode_uint16(data[5], data[6])) / 1000.0f;
+      const float acceleration_y = static_cast<int16_t>(encode_uint16(data[7], data[8])) / 1000.0f;
+      const float acceleration_z = static_cast<int16_t>(encode_uint16(data[9], data[10])) / 1000.0f;
+      const float battery_voltage = encode_uint16(data[11], data[12]) / 1000.0f;
 
       result.humidity = humidity;
       result.temperature = temperature;
@@ -43,19 +43,19 @@ bool parse_ruuvi_data_byte(const esp32_ble_tracker::adv_data_t &adv_data, RuuviP
       if (adv_data.size() != 24)
         return false;
 
-      const float temperature = (int16_t(data[0] << 8) + int16_t(data[1])) * 0.005f;
-      const float humidity = (uint16_t(data[2] << 8) | uint16_t(data[3])) / 400.0f;
-      const float pressure = ((uint16_t(data[4] << 8) | uint16_t(data[5])) + 50000.0f) / 100.0f;
-      const float acceleration_x = (int16_t(data[6] << 8) + int16_t(data[7])) / 1000.0f;
-      const float acceleration_y = (int16_t(data[8] << 8) + int16_t(data[9])) / 1000.0f;
-      const float acceleration_z = (int16_t(data[10] << 8) + int16_t(data[11])) / 1000.0f;
+      const float temperature = static_cast<int16_t>(encode_uint16(data[0], data[1])) * 0.005f;
+      const float humidity = encode_uint16(data[2], data[3]) / 400.0f;
+      const float pressure = (encode_uint16(data[4], data[5]) + 50000.0f) / 100.0f;
+      const float acceleration_x = static_cast<int16_t>(encode_uint16(data[6], data[7])) / 1000.0f;
+      const float acceleration_y = static_cast<int16_t>(encode_uint16(data[8], data[9])) / 1000.0f;
+      const float acceleration_z = static_cast<int16_t>(encode_uint16(data[10], data[11])) / 1000.0f;
 
-      const uint16_t power_info = (uint16_t(data[12] << 8) | data[13]);
+      const uint16_t power_info = encode_uint16(data[12], data[13]);
       const float battery_voltage = ((power_info >> 5) + 1600.0f) / 1000.0f;
       const float tx_power = ((power_info & 0x1F) * 2.0f) - 40.0f;
 
       const float movement_counter = float(data[14]);
-      const float measurement_sequence_number = float(uint16_t(data[15] << 8) | uint16_t(data[16]));
+      const float measurement_sequence_number = float(encode_uint16(data[15], data[16]));
 
       result.temperature = data[0] == 0x7F && data[1] == 0xFF ? NAN : temperature;
       result.humidity = data[2] == 0xFF && data[3] == 0xFF ? NAN : humidity;

esphome/components/tormatic/tormatic_protocol.h

@@ -99,7 +99,7 @@ struct MessageHeader {
 
   // payload_size returns the amount of payload bytes to be read from the uart
   // buffer after reading the header.
-  uint32_t payload_size() { return this->len - sizeof(this->type); }
+  uint32_t payload_size() { return this->len > sizeof(this->type) ? this->len - sizeof(this->type) : 0; }
 } __attribute__((packed));
 
 // StatusType denotes which 'page' of information needs to be retrieved.