Qt6.5.3 Build QtWebEngine for Windows x64. Error: transport_security_state_generator.exe failed with exit code 3221226505

[Jemand]

Hi. I am getting an error while building Qt6.5.3 QtWebEngine for Windows x64.
Here is the build configuration:

..\configure -prefix C:\qt6_x64 -opensource -debug-and-release -confirm-license -opengl desktop -nomake tests -nomake examples -skip qthttpserver -skip qtlocation -skip qtspeech -skip qtgrpc -skip qt3d -skip qtcharts -skip qtcoap -skip qtconnectivity -skip qtdatavis3d -skip qtdoc -skip qtlottie -skip qtmqtt -skip qtnetworkauth -skip qtopcua -skip qtremoteobjects -skip qtscxml -skip qtsensors -skip qtserialbus -skip qtwayland -skip qtwebengine -skip qttranslations -skip qtquickeffectmaker -skip qtquick3dphysics -skip qtgraphs  -openssl-linked -- -Wno-dev -DOPENSSL_ROOT_DIR="C:\Q\openssl-3.0.13-WIN64A\build" -DOPENSSL_INCLUDE_DIR="C:\Q\openssl-3.0.13-WIN64A\build\include" -DOPENSSL_USE_STATIC_LIBS=ON -DFFMPEG_DIR=C:\Users\user\Desktop\vcpkg\installed\x64-windows

C:\qt6_x64\bin\qt-configure-module.bat ../qtwebengine -- -Wno-dev

Here is the error:

[9063/29010] ACTION //net/http:generate_transport_security_state(//build/toolchain/win:x64)
FAILED: gen/net/http/transport_security_state_static.h
C:/Program Files/Python38/python.exe ../../../../../qtwebengine/src/3rdparty/chromium/build/gn_run_binary.py transport_security_state_generator.exe ../../../../../qtwebengine/src/3rdparty/chromium/net/http/transport_security_state_static.json.gz ../../../../../qtwebengine/src/3rdparty/chromium/net/http/transport_security_state_static.pins ../../../../../qtwebengine/src/3rdparty/chromium/net/http/transport_security_state_static.template gen/net/http/transport_security_state_static.h
transport_security_state_generator.exe failed with exit code 3221226505

Please help me.

[Esmaeil_Sooan]

Hi @Jemand
🚨 If you’re seeing this error:
transport_security_state_generator.exe failed with exit code 3221226505

This exit code corresponds to STATUS_STACK_BUFFER_OVERRUN, which usually indicates a crash due to memory corruption or an access violation. I investigated and found the root cause. 🕵️‍♂️

✅ Solution:
Navigate to the following directory in the Qt WebEngine source:

qtwebengine\src\3rdparty\chromium\net\tools\huffman_trie\trie

Then, open trie_writer.cc and modify the WriteEntries function to skip entries with empty hostnames. Here's the modified code snippet:

for (auto* const entry : entries) {
  if (entry->name().empty()) {
    LOG(INFO) << "Skipping empty hostname entry";
    continue;
  }
  auto reversed_entry =
      std::make_unique<ReversedEntry>(ReverseName(entry->name()), entry);
  reversed_entries.push_back(std::move(reversed_entry));
}

🧹 Clean up generated files:
Delete any previously built transport_security_state_generator.exe binary and related libraries from:

{your_build_dir}\qtwebengine\src\core\Release\AMD64

🔁 Rebuild:
Then rerun the build with:

cmake --build . --parallel

🎉 That should resolve the issue! Feel free to ask if you need further help.

[JonB]

@Esmaeil_Sooan
Strange that skipping an empty entry would avoid some stack overflow. If your fix really is required have you considered raising a bug to this effect at https://bugreports.qt.io/ with your proposed fix?

[Esmaeil_Sooan]

@JonB
Yes, it's definitely odd, but it fixed my issue. I think it’s better to wait and see if it also resolves @Jemand’s problem I’ll go ahead and report it as a bug.

[Esmaeil_Sooan]

@JonB
Okay, I found the issue.

It happens in the WriteDispatchTables function:

uint8_t candidate = (*start)->reversed_name.at(0);
auto sub_entries_end = start + 1;

If reversed_name is empty, this line will crash due to out-of-bounds access on .at(0).

Tracing back, this function is called from WriteEntries:

bool TrieWriter::WriteEntries(const TrieEntries& entries,
                              uint32_t* root_position) {
  if (entries.empty())
    return false;

  ReversedEntries reversed_entries;
  for (auto* const entry : entries) {
    if (entry->name().empty()) {
      LOG(INFO) << "Skipping empty hostname entry";
      continue;
    }
    auto reversed_entry =
        std::make_unique<ReversedEntry>(ReverseName(entry->name()), entry);
    reversed_entries.push_back(std::move(reversed_entry));
  }

  std::stable_sort(reversed_entries.begin(), reversed_entries.end(),
                   CompareReversedEntries);

  return WriteDispatchTables(reversed_entries.begin(), reversed_entries.end(),
                             root_position);
}

So if we don’t filter out empty entry->name() values beforehand, ReverseName() returns a vector with only the kTerminalValue, and after removing prefixes (in RemovePrefix), the reversed_name may become empty — leading to a crash when .at(0) is accessed.

Adding a check to skip empty hostnames in WriteEntries() avoids this edge case and prevents the crash.

[Esmaeil_Sooan]

bool TrieWriter::WriteDispatchTables(ReversedEntries::iterator start,
                                     ReversedEntries::iterator end,
                                     uint32_t* position) {
  DCHECK(start != end) << "No entries passed to WriteDispatchTables";

  TrieBitBuffer writer;

  std::vector<uint8_t> prefix = LongestCommonPrefix(start, end);
  LOG(INFO) << "Longest common prefix size: " << prefix.size();
  writer.WriteSize(prefix.size());
  LOG(INFO) << "Prefix size: " << prefix.size();

  if (prefix.size()) {
    for (uint8_t c : prefix) {
      writer.WriteChar(c, huffman_table_, huffman_builder_);
    }
  }
  LOG(INFO) << "Prefix written";

  RemovePrefix(prefix.size(), start, end);
  LOG(INFO) << "Prefix removed";
  int32_t last_position = -1;

  while (start != end) {
    uint8_t candidate = (*start)->reversed_name.at(0);
    auto sub_entries_end = start + 1;

    for (; sub_entries_end != end; sub_entries_end++) {
      if ((*sub_entries_end)->reversed_name.at(0) != candidate) {
        break;
      }
    }
    LOG(INFO)<< "Sub entries size: " << sub_entries_end - start;

    writer.WriteChar(candidate, huffman_table_, huffman_builder_);
    LOG(INFO)<< "Candidate written: " << candidate;
    if (candidate == kTerminalValue) {
      if (sub_entries_end - start != 1) {
        return false;
      }
      if (!(*start)->entry->WriteEntry(&writer)) {
        return false;
      }
      LOG(INFO)<< "Entry written";
    } else {
      RemovePrefix(1, start, sub_entries_end);
      uint32_t table_position;
      if (!WriteDispatchTables(start, sub_entries_end, &table_position)) {
        return false;
      }
      LOG(INFO)<< "Dispatch table written";

      writer.WritePosition(table_position, &last_position);
      LOG(INFO)<< "Position written: " << table_position;
    }

    start = sub_entries_end;
  }

  writer.WriteChar(kEndOfTableValue, huffman_table_, huffman_builder_);
  LOG(INFO)<< "End of table written";

  *position = buffer_.position();
  writer.Flush();
  writer.WriteToBitWriter(&buffer_);
  LOG(INFO)<< "Buffer flushed";
  return true;
}

[JonB]

@Esmaeil_Sooan said in Qt6.5.3 Build QtWebEngine for Windows x64. Error: transport_security_state_generator.exe failed with exit code 3221226505:

Adding a check to skip empty hostnames in WriteEntries() avoids this edge case and prevents the crash.

I am just surprised this has not come up more often for other people. Maybe having an empty entry there is not common, I do not know? Anyway I urge you to kindly raise what you think is a bug and your solution at TQtC bugs Url as I posted earlier. Thank you.

[Esmaeil_Sooan]

@JonB
Sure, thank you.

[Esmaeil_Sooan]

I've reported this issue as a bug at:
https://bugreports.qt.io/browse/QTBUG-136652