Nullptr topic causes panic with ESP32 when MQTT message is read chunked

aaliddell commented 10 months ago

The problem

When a received MQTT message is read in multiple chunks under esp32 MQTT backend, any messages after the first will have a nullptr topic pointer. This then causes a std::logic_error to be raised when creating a std::string for the topic in mqtt_client, leading to a panic and reboot.

Topic is null on subsequent chunks from here: https://github.com/espressif/esp-mqtt/blob/7894dd0ace9ef8b035e3686d2767324540c1cfea/mqtt_client.c#L1090 Nullptr gets propagated here due to empty topic: https://github.com/esphome/esphome/blame/32e3f2623973f45bd37b6b0dc956adcd82a45e77/esphome/components/mqtt/mqtt_backend_esp32.cpp#L146 Nullptr causes std::logic_error here in std::string constructor (implicit cast): https://github.com/esphome/esphome/blob/32e3f2623973f45bd37b6b0dc956adcd82a45e77/esphome/components/mqtt/mqtt_client.cpp#L48

The topic needs to be stored from the first segment and then used once all segments have been read. Will send a PR shortly.

Which version of ESPHome has the issue?

2023.9.1 but still present in latest

What type of installation are you using?

Docker

Which version of Home Assistant has the issue?

N/A

What platform are you using?

ESP32-IDF

Board

esp32dev

Component causing the issue

mqtt

Example YAML snippet

esphome:
  name: Something

esp32:
  board: esp32dev
  framework:
    type: esp-idf

mqtt:
  id: mqtt_client
  broker: 1.2.3.4
  username: username
  password: password
  on_message:
  # Subscription required to cause bug
    - topic: some/topic
      then:
        - logger.log: "Message"

wifi:
  ssid: ssid
  password: password

Anything in the logs that might be useful for us?

0x40084236: panic_abort at /config/.esphome/platformio/packages/framework-espidf/components/esp_system/panic.c:408
0x4008c32d: esp_system_abort at /config/.esphome/platformio/packages/framework-espidf/components/esp_system/esp_system.c:137
0x40092306: abort at /config/.esphome/platformio/packages/framework-espidf/components/newlib/abort.c:46
0x40164a0a: __wrap__Unwind_RaiseException at ??:?
0x401636b7: __cxa_throw at /builds/idf/crosstool-NG/.build/xtensa-esp32-elf/src/gcc/libstdc++-v3/libsupc++/eh_throw.cc:90
0x40163f5b: std::__throw_logic_error(char const*) at /builds/idf/crosstool-NG/.build/xtensa-esp32-elf/src/gcc/libstdc++-v3/src/c++11/functexcept.cc:66 (discriminator 2)
0x400d7cfa: void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char const*>(char const*, char const*, std::forward_iterator_tag) at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/basic_string.tcc:212
 (inlined by) void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct_aux<char const*>(char const*, char const*, std::__false_type) at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/basic_string.h:236
 (inlined by) void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char const*>(char const*, char const*) at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/basic_string.h:255
 (inlined by) std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&) at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/basic_string.h:516
0x400d8310: std::_Function_handler<void (char const*, char const*, unsigned int, unsigned int, unsigned int), esphome::mqtt::MQTTClientComponent::setup()::{lambda(char const*, char const*, unsigned int, unsigned int, unsigned int)#1}>::_M_invoke(std::_Any_data const&, char const*&&, std::_Any_data const&, unsigned int&&, char const*&&, char const*&&) at /config/.esphome/build/<snip>/src/esphome/components/mqtt/mqtt_client.cpp:48
 (inlined by) _M_invoke at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/std_function.h:297
0x400d6e31: std::function<void (char const*, char const*, unsigned int, unsigned int, unsigned int)>::operator()(char const*, char const*, unsigned int, unsigned int, unsigned int) const at /config/.esphome/platformio/packages/toolchain-xtensa-esp32@8.4.0+2021r2-patch5/xtensa-esp32-elf/include/c++/8.4.0/bits/std_function.h:687
 (inlined by) esphome::CallbackManager<void (char const*, char const*, unsigned int, unsigned int, unsigned int)>::call(char const*, char const*, unsigned int, unsigned int, unsigned int) at /config/.esphome/build/<snip>/src/esphome/core/helpers.h:482
 (inlined by) esphome::mqtt::MQTTBackendESP32::mqtt_event_handler_(esphome::mqtt::Event const&) at /config/.esphome/build/<snip>/src/esphome/components/mqtt/mqtt_backend_esp32.cpp:146
0x400d6f87: esphome::mqtt::MQTTBackendESP32::loop() at /config/.esphome/build/<snip>/src/esphome/components/mqtt/mqtt_backend_esp32.cpp:103
 (inlined by) esphome::mqtt::MQTTBackendESP32::loop() at /config/.esphome/build/<snip>/src/esphome/components/mqtt/mqtt_backend_esp32.cpp:98
0x400d8643: esphome::mqtt::MQTTClientComponent::loop() at /config/.esphome/build/<snip>/src/esphome/components/mqtt/mqtt_client.cpp:295
0x4017a169: esphome::Component::call_loop() at /config/.esphome/build/<snip>/src/esphome/core/component.cpp:76
0x4017a255: esphome::Component::call() at /config/.esphome/build/<snip>/src/esphome/core/component.cpp:98
0x400e0218: esphome::Application::loop() at /config/.esphome/build/<snip>/src/esphome/core/application.cpp:74 (discriminator 2)
0x400e40c6: loop() at /config/<snip>.yaml:48

Additional information

No response

github-actions[bot] commented 6 months ago

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

aaliddell commented 6 months ago

.

esphome / issues