Crash on DNS lookup

[cacharle]

I'm getting an inconsistent crash in some unit tests which spin up a websocket server/client.

Unexpected error 9 on netlink descriptor 7.

Thread 1393 "ws://127.0.0.1:" received signal SIGABRT, Aborted.
[Switching to Thread 0x7ffff540e680 (LWP 34520)]
0x00007ffff64a774c in ?? () from /usr/lib/libc.so.6

(gdb) bt
#0  0x00007ffff64a774c in ?? () from /usr/lib/libc.so.6
#1  0x00007ffff644ddc0 in raise () from /usr/lib/libc.so.6
#2  0x00007ffff643557a in abort () from /usr/lib/libc.so.6
#3  0x00007ffff64365c9 in ?? () from /usr/lib/libc.so.6
#4  0x00007ffff649ac89 in __libc_fatal () from /usr/lib/libc.so.6
#5  0x00007ffff653d7c8 in __netlink_assert_response () from /usr/lib/libc.so.6
#6  0x00007ffff653cf47 in ?? () from /usr/lib/libc.so.6
#7  0x00007ffff655583a in getaddrinfo () from /usr/lib/libc.so.6
#8  0x0000555556fb4561 in ix::DNSLookup::getAddrInfo (this=0x7fffe80110d0, hostname="127.0.0.1", port=9999, errMsg="")
    at /home/charles/git/vcpkg/buildtrees/ixwebsocket/src/v11.4.5-fb1eb11bb0.clean/ixwebsocket/IXDNSLookup.cpp:65
#9  0x0000555556fb4aba in ix::DNSLookup::run (this=0x7fffe80110d0, self=std::weak_ptr<ix::DNSLookup> (use count 2, weak count 3) = {...}, hostname="127.0.0.1", port=9999)
    at /home/charles/git/vcpkg/buildtrees/ixwebsocket/src/v11.4.5-fb1eb11bb0.clean/ixwebsocket/IXDNSLookup.cpp:160
#10 0x0000555556fb722d in std::__invoke_impl<void, void (ix::DNSLookup::*)(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int), ix::DNSLookup*, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> (
    __f=@0x7fffe8012768: (void (ix::DNSLookup::*)(ix::DNSLookup * const, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int)) 0x555556fb4a5a <ix::DNSLookup::run(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int)>, __t=@0x7fffe8012760: 0x7fffe80110d0) at /usr/include/c++/15.1.1/bits/invoke.h:76
#11 0x0000555556fb7095 in std::__invoke<void (ix::DNSLookup::*)(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int), ix::DNSLookup*, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> (
    __fn=@0x7fffe8012768: (void (ix::DNSLookup::*)(ix::DNSLookup * const, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int)) 0x555556fb4a5a <ix::DNSLookup::run(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int)>) at /usr/include/c++/15.1.1/bits/invoke.h:98
#12 0x0000555556fb6f43 in std::thread::_Invoker<std::tuple<void (ix::DNSLookup::*)(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int), ix::DNSLookup*, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> >::_M_invoke<0ul, 1ul, 2ul, 3ul, 4ul> (this=0x7fffe8012728)
    at /usr/include/c++/15.1.1/bits/std_thread.h:303
#13 0x0000555556fb6e5a in std::thread::_Invoker<std::tuple<void (ix::DNSLookup::*)(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int), ix::DNSLookup*, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> >::operator() (this=0x7fffe8012728) at /usr/include/c++/15.1.1/bits/std_thread.h:310
#14 0x0000555556fb6b5a in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (ix::DNSLookup::*)(std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int), ix::DNSLookup*, std::weak_ptr<ix::DNSLookup>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int> > >::_M_run (this=0x7fffe8012720)
    at /usr/include/c++/15.1.1/bits/std_thread.h:255
#15 0x00007ffff66e51a4 in std::execute_native_thread_routine (__p=0x7fffe8012720) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:104
#16 0x00007ffff64a57eb in ?? () from /usr/lib/libc.so.6
#17 0x00007ffff652918c in ?? () from /usr/lib/libc.so.6

It happens on the getaddrinfo call at

IXWebSocket/ixwebsocket/IXDNSLookup.cpp

Line 65 in c5a02f1

int getaddrinfo_result = getaddrinfo(hostname.c_str(), sport.c_str(), &hints, &res);

The unit tests worked fine for a long time, the issue only appeared when I shuffle them and run them over and over again.

I'm probably just not cleaning up properly at some point and I'll investigate that but I think the library shouldn't crash.

I'm using v11.4.5