stop_accepting_connections overload action causes crash #13514
Description
When the stop_accepting_connections changes from active to inactive or vice-versa around the same time as an LDS update, it can result in a segmentation fault due to trying to dereference a null pointer. Thanks to @Christoska for reporting this first to envoy-security@. Since the issue can be easily mitigated (by removing the entry for the stop_accepting_connections action from the overload manager config), the window in which it can be triggered is small, and the only possible result is a segfault and crash, this can go through the regular bug process.
Concretely, this is what happens:
- An LDS update comes that removes a listener.
- This results in a call to ListenerManagerImpl::removeListener,
- which calls drainListener, which calls stopListener,
- which calls Worker::stopListener.
- WorkerImpl::stopListener calls ConnectionHandler::stopListeners,
- which calls ActiveListener::shutdownListener.
- ActiveTcpListener::shutdownListener deletes the unique_ptr listener_ member.
Repro steps:
Enable the envoy.overload_actions.stop_accepting_connection overload action.
Run Envoy near the overload threshold such that the action changes state frequently.
Send LDS updates for Envoy via the control server.
Config:
Overload config that was causing the issue:
overload_manager:
refresh_interval:
seconds: 0
nanos: 250000000
resource_monitors:
- name: "envoy.resource_monitors.fixed_heap"
typed_config:
"@type": type.googleapis.com/envoy.config.resource_monitor.fixed_heap.v2alpha.FixedHeapConfig
max_heap_size_bytes: 943718400
actions:
- name: "envoy.overload_actions.shrink_heap"
triggers:
- name: "envoy.resource_monitors.fixed_heap"
threshold:
value: 0.90
- name: "envoy.overload_actions.disable_http_keepalive"
triggers:
- name: "envoy.resource_monitors.fixed_heap"
threshold:
value: 0.95
- name: "envoy.overload_actions.stop_accepting_connections"
triggers:
- name: "envoy.resource_monitors.fixed_heap"
threshold:
value: 0.97
- name: "envoy.overload_actions.stop_accepting_requests"
triggers:
- name: "envoy.resource_monitors.fixed_heap"
threshold:
value: 0.99Call Stack:
From examining the core dump with GDB:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x000055d1d2914fbe in Envoy::Server::ConnectionHandlerImpl::ActiveTcpListener::pauseListening (
this=0x55d1d6782b40)
at bazel-out/k8-dbg/bin/source/server/_virtual_includes/connection_handler_lib/server/connection_handler_impl.h:133
133 bazel-out/k8-dbg/bin/source/server/_virtual_includes/connection_handler_lib/server/connection_handler_impl.h: No such file or directory.
[Current thread is 1 (Thread 0x7fd37c444700 (LWP 23))]
Missing separate debuginfos, use: yum debuginfo-install cesp-envoy-debug-1.14.4-1.x86_64
(gdb) bt
#0 0x000055d1d2914fbe in Envoy::Server::ConnectionHandlerImpl::ActiveTcpListener::pauseListening (
this=0x55d1d6782b40)
at bazel-out/k8-dbg/bin/source/server/_virtual_includes/connection_handler_lib/server/connection_handler_impl.h:133
#1 0x000055d1d290a27a in Envoy::Server::ConnectionHandlerImpl::disableListeners (this=0x55d1d5711b30)
at source/server/connection_handler_impl.cc:74
#2 0x000055d1d29000a6 in Envoy::Server::WorkerImpl::stopAcceptingConnectionsCb (this=0x55d1d56ed380,
state=Envoy::Server::OverloadActionState::Active) at source/server/worker_impl.cc:125
#3 0x000055d1d29015de in Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0::operator()(Envoy::Server::OverloadActionState) const (this=0x55d1d56df778,
state=Envoy::Server::OverloadActionState::Active) at source/server/worker_impl.cc:34
#4 0x000055d1d29015a1 in std::__1::__invoke<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0&, Envoy::Server::OverloadActionState> (__f=...,
__args=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active)
at /opt/llvm/bin/../include/c++/v1/type_traits:3530
#5 0x000055d1d2901542 in std::__1::__invoke_void_return_wrapper<void>::__call<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0&, Envoy::Server::OverloadActionState>(Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0&, Envoy::Server::OverloadActionState&&) (
__args=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active,
__args=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active)
at /opt/llvm/bin/../include/c++/v1/__functional_base:348
#6 0x000055d1d2901502 in std::__1::__function::__alloc_func<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0, std::__1::allocator<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0>, void (Envoy::Server::OverloadActionState)>::operator()(Envoy::Server::OverloadActionState&&) (this=0x55d1d56df778,
__arg=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active)
at /opt/llvm/bin/../include/c++/v1/functional:1533
#7 0x000055d1d2900643 in std::__1::__function::__func<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0, std::__1::allocator<Envoy::Server::WorkerImpl::WorkerImpl(Envoy::ThreadLocal::Instance&, Envoy::ListenerHooks&, std::__1::unique_ptr<Envoy::Event::Dispatcher, std::__1::default_delete<Envoy::Event::Dispatcher> >&&, std::__1::unique_ptr<Envoy::Network::ConnectionHandler, std::__1::default_delete<Envoy::Network::ConnectionHandler> >, Envoy::Server::OverloadManager&, Envoy::Api::Api&, std::__1::basic--Type <RET> for more, q to quit, c to continue without paging--
c:OverloadActionState)>::operator()(Envoy::Server::OverloadActionState&&) (this=0x55d1d56df770, __arg=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active) at /opt/llvm/bin/../include/c++/v1/functional:1707
#8 0x000055d1d2f2e08d in std::__1::__function::__value_func<void (Envoy::Server::OverloadActionState)>::operator()(Envoy::Server::OverloadActionState&&) const (this=0x55d1d56df770,
__args=@0x7fd37c42fc64: Envoy::Server::OverloadActionState::Active) at /opt/llvm/bin/../include/c++/v1/functional:1860
#9 0x000055d1d2f2e02f in std::__1::function<void (Envoy::Server::OverloadActionState)>::operator()(Envoy::Server::OverloadActionState) const (this=0x55d1d56df770, __arg=Envoy::Server::OverloadActionState::Active)
at /opt/llvm/bin/../include/c++/v1/functional:2419
#10 0x000055d1d2f1b875 in Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}::operator()() const (this=0x7fd37c42fd98) at source/server/overload_manager_impl.cc:217
#11 0x000055d1d2f1b82d in std::__1::__invoke<Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}&> (__f=...) at /opt/llvm/bin/../include/c++/v1/type_traits:3530
#12 0x000055d1d2f1b7dd in std::__1::__invoke_void_return_wrapper<void>::__call<Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}&>(Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}&) (__args=...)
at /opt/llvm/bin/../include/c++/v1/__functional_base:348
#13 0x000055d1d2f1b7ad in std::__1::__function::__alloc_func<Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}, std::__1::allocator<{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}>, void ()>::operator()() (this=0x7fd37c42fd98) at /opt/llvm/bin/../include/c++/v1/functional:1533
#14 0x000055d1d2f1a8de in std::__1::__function::__func<Envoy::Server::OverloadManagerImpl::updateResourcePressure(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, double)::$_2::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >&) const::{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}::operator()(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&) const::{lambda()#1}, std::__1::allocator<{lambda(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, Envoy::Server::OverloadManagerImpl::ActionCallback>&)#1}>, void ()>::operator()()
(this=0x7fd37c42fd90) at /opt/llvm/bin/../include/c++/v1/functional:1707
#15 0x000055d1d0be5435 in std::__1::__function::__value_func<void ()>::operator()() const (this=0x7fd37c42fd90) at /opt/llvm/bin/../include/c++/v1/functional:1860
#16 0x000055d1d0be50d5 in std::__1::function<void ()>::operator()() const (this=0x7fd37c42fd90) at /opt/llvm/bin/../include/c++/v1/functional:2419
#17 0x000055d1d292aa29 in Envoy::Event::DispatcherImpl::runPostCallbacks (this=0x55d1d576fc80) at source/common/event/dispatcher_impl.cc:225
#18 0x000055d1d292d438 in Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1::operator()() const (this=0x55d1d57a4a48) at source/common/event/dispatcher_impl.cc:43
#19 0x000055d1d292d3fd in std::__1::__invoke<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1&> (__f=...) at /opt/llvm/bin/../include/c++/v1/type_traits:3530
#20 0x000055d1d292d3ad in std::__1::__invoke_void_return_wrapper<void>::__call<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1&>(Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1&) (__args=...) at /opt/llvm/bin/../include/c++/v1/__functional_base:348
#21 0x000055d1d292d37d in std::__1::__function::__alloc_func<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1, std::__1::allocator<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1>, void ()>::operator()() (this=0x55d1d57a4a48) at /opt/llvm/bin/../include/c++/v1/functional:1533
#22 0x000055d1d292c4ce in std::__1::__function::__func<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1, std::__1::allocator<Envoy::Event::DispatcherImpl::DispatcherImpl(std::__1::unique_ptr<Envoy::Buffer::WatermarkFactory, std::__1::default_delete<Envoy::Buffer::WatermarkFactory> >&&, Envoy::Api::Api&, Envoy::Event::TimeSystem&)::$_1>, void ()>::operator()() (this=0x55d1d57a4a40) at /opt/llvm/bin/../include/c++/v1/functional:1707
#23 0x000055d1d0be5435 in std::__1::__function::__value_func<void ()>::operator()() const (this=0x55d1d57a4a40) at /opt/llvm/bin/../include/c++/v1/functional:1860
#24 0x000055d1d0be50d5 in std::__1::function<void ()>::operator()() const (this=0x55d1d57a4a40) at /opt/llvm/bin/../include/c++/v1/functional:2419
#25 0x000055d1d296a18d in Envoy::Event::TimerImpl::TimerImpl(Envoy::CSmartPtr<event_base, &event_base_free>&, std::__1::function<void ()>, Envoy::Event::Dispatcher&)::$_0::operator()(int, short, void*) const (this=0xffffffff,
arg=0x55d1d57a49c0) at source/common/event/timer_impl.cc:15
#26 0x000055d1d296a136 in Envoy::Event::TimerImpl::TimerImpl(Envoy::CSmartPtr<event_base, &event_base_free>&, std::__1::function<void ()>, Envoy::Event::Dispatcher&)::$_0::__invoke(int, short, void*) (arg=0x55d1d57a49c0)
at source/common/event/timer_impl.cc:15
#27 0x000055d1d343f961 in event_process_active_single_queue (base=0x55d1d5451340, activeq=0x55d1d5431e90, max_to_process=2147483647, endtime=0x0)
at /build/tmp/_bazel_bazel/b570b5ccd0454dc9af9f65ab1833764d/sandbox/processwrapper-sandbox/31/execroot/envoy/external/com_github_libevent_libevent/event.c:1713
#28 0x000055d1d343a05a in event_process_active (base=0x55d1d5451340) at /build/tmp/_bazel_bazel/b570b5ccd0454dc9af9f65ab1833764d/sandbox/processwrapper-sandbox/31/execroot/envoy/external/com_github_libevent_libevent/event.c:1805
#29 0x000055d1d3438f2c in event_base_loop (base=0x55d1d5451340, flags=0)
at /build/tmp/_bazel_bazel/b570b5ccd0454dc9af9f65ab1833764d/sandbox/processwrapper-sandbox/31/execroot/envoy/external/com_github_libevent_libevent/event.c:2047
--Type <RET> for more, q to quit, c to continue without paging--
#30 0x000055d1d2968cd8 in Envoy::Event::LibeventScheduler::run (this=0x55d1d576fcd0, mode=Envoy::Event::Dispatcher::RunType::Block) at source/common/event/libevent_scheduler.cc:47
#31 0x000055d1d292a93a in Envoy::Event::DispatcherImpl::run (this=0x55d1d576fc80, type=Envoy::Event::Dispatcher::RunType::Block) at source/common/event/dispatcher_impl.cc:197
#32 0x000055d1d28ffef1 in Envoy::Server::WorkerImpl::threadRoutine (this=0x55d1d56ed380, guard_dog=...) at source/server/worker_impl.cc:110
#33 0x000055d1d2905aec in Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3::operator()() const (this=0x55d1d70743d8) at source/server/worker_impl.cc:75
#34 0x000055d1d2905aad in std::__1::__invoke<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3&> (__f=...) at /opt/llvm/bin/../include/c++/v1/type_traits:3530
#35 0x000055d1d2905a5d in std::__1::__invoke_void_return_wrapper<void>::__call<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3&>(Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3&) (__args=...)
at /opt/llvm/bin/../include/c++/v1/__functional_base:348
#36 0x000055d1d2905a2d in std::__1::__function::__alloc_func<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3, std::__1::allocator<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3>, void ()>::operator()() (this=0x55d1d70743d8) at /opt/llvm/bin/../include/c++/v1/functional:1533
#37 0x000055d1d2904b5e in std::__1::__function::__func<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3, std::__1::allocator<Envoy::Server::WorkerImpl::start(Envoy::Server::GuardDog&)::$_3>, void ()>::operator()()
(this=0x55d1d70743d0) at /opt/llvm/bin/../include/c++/v1/functional:1707
#38 0x000055d1d0be5435 in std::__1::__function::__value_func<void ()>::operator()() const (this=0x55d1d70743d0) at /opt/llvm/bin/../include/c++/v1/functional:1860
#39 0x000055d1d0be50d5 in std::__1::function<void ()>::operator()() const (this=0x55d1d70743d0) at /opt/llvm/bin/../include/c++/v1/functional:2419
#40 0x000055d1d35b4672 in Envoy::Thread::ThreadImplPosix::ThreadImplPosix(std::__1::function<void ()>)::$_0::operator()(void*) const (this=0x55d1d70743c0, arg=0x55d1d70743c0) at source/common/common/posix/thread_impl.cc:33
#41 0x000055d1d35b4645 in Envoy::Thread::ThreadImplPosix::ThreadImplPosix(std::__1::function<void ()>)::$_0::__invoke(void*) (arg=0x55d1d70743c0) at source/common/common/posix/thread_impl.cc:32
#42 0x00007fd38201a2de in start_thread () from /lib64/libpthread.so.0
#43 0x00007fd381d4be83 in clone () from /lib64/libc.so.6