diff --git a/esphome/components/pn532_spi/pn532_spi.cpp b/esphome/components/pn532_spi/pn532_spi.cpp index 118421c47..553c6d26a 100644 --- a/esphome/components/pn532_spi/pn532_spi.cpp +++ b/esphome/components/pn532_spi/pn532_spi.cpp @@ -88,9 +88,10 @@ bool PN532Spi::read_response(uint8_t command, std::vector &data) { #endif ESP_LOGV(TAG, "Header data: %s", format_hex_pretty_to(hex_buf, sizeof(hex_buf), header.data(), header.size())); - if (header[0] != 0x00 && header[1] != 0x00 && header[2] != 0xFF) { + if (header[0] != 0x00 || header[1] != 0x00 || header[2] != 0xFF) { // invalid packet ESP_LOGV(TAG, "read data invalid preamble!"); + this->disable(); return false; } @@ -100,15 +101,20 @@ bool PN532Spi::read_response(uint8_t command, std::vector &data) { if (!valid_header) { ESP_LOGV(TAG, "read data invalid header!"); + this->disable(); return false; } - // full length of message, including command response + // full length of message, including command response (minimum 2: TFI + command response) uint8_t full_len = header[3]; + if (full_len < 2) { + ESP_LOGV(TAG, "read data has no payload"); + this->disable(); + return false; + } + // length of data, excluding command response uint8_t len = full_len - 1; - if (full_len == 0) - len = 0; ESP_LOGV(TAG, "Reading response of length %d", len);