Segfault on Linux after manual compilation

[proycon]

Since the AppImage or binary wasn't working for me on my Arch Linux system (I didn't get any audio, communication problem with pipewire perhaps? See #234), I compiled xpilot from scratch. After fixing a small compilation problem (#233) I ran into a segfault somewhere deep in the SSL certificate handling.

The segfault happens one or two seconds after launch, the GUI shows for a bit and shows the 'first time' dialog (which I don't really get the chance to interact with before the segfault happens).

Gdb traceback follows:

Thread 1 "xPilot" received signal SIGSEGV, Segmentation fault.
0x0000555556168380 in ASN1_OCTET_STRING_it ()
(gdb) bt
#0  0x0000555556168380 in ASN1_OCTET_STRING_it ()
#1  0x00007fff9abdfad3 in operator() (__closure=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:255
#2  QScopeGuard<QTlsPrivate::(anonymous namespace)::x509ExtensionToValue(X509_EXTENSION*)::<lambda()> >::~QScopeGuard
    (this=<optimized out>, this=<optimized out>) at /usr/src/debug/qt6-base/qtbase/src/corelib/tools/qscopeguard.h:41
#3  QTlsPrivate::(anonymous namespace)::x509ExtensionToValue (ext=0x555556ddadb0)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:351
#4  QTlsPrivate::X509CertificateOpenSSL::convertExtension (ext=0x555556ddadb0)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:929
#5  QTlsPrivate::X509CertificateOpenSSL::parseExtensions (this=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:906
#6  QTlsPrivate::X509CertificateOpenSSL::certificateFromX509 (x509=x509@entry=0x5555565bc3a0)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:573
#7  0x00007fff9abe0a7b in QTlsPrivate::X509CertificateOpenSSL::certificatesFromPem (pem=..., count=-1)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qx509_openssl.cpp:746
#8  0x00007ffff663cd94 in QSslCertificate::fromData (data=..., format=format@entry=QSsl::Pem)
    at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslcertificate.cpp:757
#9  0x00007ffff663e0ad in QSslCertificate::fromPath
    (path=<optimized out>, format=format@entry=QSsl::Pem, syntax=syntax@entry=QSslCertificate::PatternSyntax::FixedString)
    at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslcertificate.cpp:671
#10 0x00007fff9abd7b91 in QTlsPrivate::systemCaCertificates ()
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qtlsbackend_openssl.cpp:402
#11 0x00007fff9abd8cd0 in QTlsBackendOpenSSL::systemCaCertificates (this=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qtlsbackend_openssl.cpp:417
#12 QTlsBackendOpenSSL::ensureCiphersAndCertsLoaded (this=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/plugins/tls/openssl/qtlsbackend_openssl.cpp:221
#13 0x00007ffff66cbdb0 in QSslSocketPrivate::ensureInitialized ()
    at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslsocket.cpp:2033
#14 QSslSocketPrivate::ensureInitialized () at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslsocket.cpp:2026
#15 QSslConfigurationPrivate::defaultConfiguration () at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslsocket.cpp:2259
#16 0x00007ffff65fafc9 in QSslConfiguration::defaultConfiguration ()
    at /usr/src/debug/qt6-base/qtbase/src/network/ssl/qsslconfiguration.cpp:1095
#17 QNetworkRequest::sslConfiguration (this=0x7fffffffc780)
    at /usr/src/debug/qt6-base/qtbase/src/network/access/qnetworkrequest.cpp:784
#18 0x00007ffff65e2502 in QNetworkReplyHttpImpl::QNetworkReplyHttpImpl
    (this=0x555556497e00, manager=<optimized out>, request=..., operation=<synthetic pointer>: <optimized out>, outgoingData=<optimized out>) at /usr/src/debug/qt6-base/qtbase/src/network/access/qnetworkreplyhttpimpl.cpp:158
#19 QNetworkAccessManager::createRequest
    (this=<optimized out>, op=<optimized out>, originalReq=<optimized out>, outgoingData=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/network/access/qnetworkaccessmanager.cpp:1318
#20 0x00007ffff65db361 in QNetworkAccessManager::get (this=<optimized out>, request=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase/src/network/access/qnetworkaccessmanager.cpp:780
#21 0x00005555556f6bad in auto xpilot::ServerListManager::DownloadStatusInfo(QString const&)::{lambda(auto:1, auto:2)#1}::operator()<QtPromise::QPromiseResolve<QString>, QtPromise::QPromiseReject<QString> >(QtPromise::QPromiseResolve<QString>, QtPromise::QPromiseReject<QString>) const ()
#22 0x00005555556f6e47 in QtPromise::QPromiseBase<QString>::QPromiseBase<xpilot::ServerListManager::DownloadStatusInfo(QString const&)::{lambda(auto:1, auto:2)#1}, 0>(xpilot::ServerListManager::DownloadStatusInfo(QString const&)::{lambda(auto:1, auto:2)#1}) ()
#23 0x00005555556f5fe2 in QtPromise::QPromise<QString>::QPromise<xpilot::ServerListManager::DownloadStatusInfo(QString const&)::{lambda(auto:1, auto:2)#1}>(xpilot::ServerListManager::DownloadStatusInfo(QString const&)::{lambda(auto:1, auto:2)#1}&&) ()
#24 0x00005555556f5bd6 in xpilot::ServerListManager::DownloadStatusInfo(QString const&) ()
#25 0x00005555556f5a8c in xpilot::ServerListManager::PerformServerListDownload(QString const&) ()
#26 0x000055555564a326 in xpilot::Main(int, char**)::{lambda()#1}::operator()() const ()

PS: It also seems that because of these failed attempts, I might be locked out by the vatsim server currently? I get "Network server address returned null, possibly due to a failed DNS lookup." in the AppImage-version of the client now.

[justinshannon]

Unfortunately, even if you’re able to successfully compile xPilot yourself, you won’t be able to actually connect it to the VATSIM network. There’s a proprietary client authentication library that is included when the client is built for release.

I see you closed #234. Did you manage to get the audio to work?

[proycon]

Ah, that's unfortunate, I didn't realize there was a proprietary component. Is that something VATSIM imposes to limit access to their network to certain clients? Would be nice if they could rely fully on FOSS software instead...

I see you closed #234. Did you manage to get the audio to work?

Yes, that was a false alarm, the audio was working fine despite the warnings. It was just user error on my part in understanding how things works exactly (it was my first time using vatsim).

[justinshannon]

Is that something VATSIM imposes to limit access to their network to certain clients?

Yes, this is the reasoning.