[runtime_image] Add check for dimensions in BMP (#18800)

esphome/components/runtime_image/bmp_decoder.cpp

@@ -80,6 +80,10 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
 
     this->width_ = encode_uint32(buffer[21], buffer[20], buffer[19], buffer[18]);
     this->height_ = encode_uint32(buffer[25], buffer[24], buffer[23], buffer[22]);
+    if (this->width_ <= 0 || this->height_ <= 0) {
+      ESP_LOGE(TAG, "Invalid image dimensions: (%zdx%zd)", this->width_, this->height_);
+      return DECODE_ERROR_UNSUPPORTED_FORMAT;
+    }
     this->bits_per_pixel_ = encode_uint16(buffer[29], buffer[28]);
     this->compression_method_ = encode_uint32(buffer[33], buffer[32], buffer[31], buffer[30]);
     this->image_data_size_ = encode_uint32(buffer[37], buffer[36], buffer[35], buffer[34]);