Crash in NetBox after some inactivity

[exkrexpexfex]

Far Manager version

3.0.6300.0 x64 (15c0671)

OS version

10.0.17763.2565

Other software

No response

Steps to reproduce

Opent SFTP connection to NetBox, wait for inactivity timeout

Expected behavior

Far doesn't crash

Actual behavior

Far crashed bug_report.txt

[yegor-mialyk]

Have you tried the latest version? With your "so called" steps to reproduce, I do not have any issues. Maybe you need to share more details.

[alabuzhev]

Looks like a pure Netbox issue to me. Stack with symbols:

001F97A5   NetBox.dll!nbstr_release(CMStringData * pThis), Line 90
00010C90   NetBox.dll!CMSimpleStringT<wchar_t>::~CMSimpleStringT<wchar_t>(void), Line 53
00512D8A   NetBox.dll!_CallSettingFrameEncoded(void), Line 183
00508BD7   NetBox.dll!__FrameHandler4::FrameUnwindToState(unsigned __int64 * pRN, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, int targetState), Line 1150
005039F5   NetBox.dll!__FrameHandler4::FrameUnwindToEmptyState(unsigned __int64 * pRN, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo), Line 234
00507B39   NetBox.dll!__InternalCxxFrameHandler<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, int CatchDepth, unsigned __int64 * pMarkerRN, unsigned char recursive), Line 355
00507C71   NetBox.dll!__InternalCxxFrameHandlerWrapper<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, int CatchDepth, unsigned __int64 * pMarkerRN, unsigned char recursive), Line 236
00504405   NetBox.dll!__CxxFrameHandler4(EHExceptionRecord * pExcept, unsigned __int64 RN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC), Line 306
000A4AAF   ntdll.dll!_chkstk+0x19F
0000610C   ntdll.dll!RtlUnwindEx+0x51C
00503FDE   NetBox.dll!__FrameHandler4::UnwindNestedFrames(unsigned __int64 * pFrame, EHExceptionRecord * pExcept, _CONTEXT * pContext, unsigned __int64 * pEstablisher, void * Handler, FH4::FuncInfo4 * __formal, int TargetUnwindState, int CatchState, FH4::HandlerType4 * pCatch, _xDISPATCHER_CONTEXT * pDC, unsigned char recursive), Line 688
00506589   NetBox.dll!CatchIt<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, FH4::HandlerType4 * pCatch, const _s_CatchableType * pConv, FH4::TryBlockMapEntry4 * pEntry, int CatchDepth, unsigned __int64 * pMarkerRN, unsigned char IsRethrow, unsigned char recursive), Line 1374
00506E01   NetBox.dll!FindHandler<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, unsigned char recursive, int CatchDepth, unsigned __int64 * pMarkerRN), Line 629
00507C0C   NetBox.dll!__InternalCxxFrameHandler<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, int CatchDepth, unsigned __int64 * pMarkerRN, unsigned char recursive), Line 403
00507C71   NetBox.dll!__InternalCxxFrameHandlerWrapper<__FrameHandler4>(EHExceptionRecord * pExcept, unsigned __int64 * pRN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC, FH4::FuncInfo4 * pFuncInfo, int CatchDepth, unsigned __int64 * pMarkerRN, unsigned char recursive), Line 236
00504405   NetBox.dll!__CxxFrameHandler4(EHExceptionRecord * pExcept, unsigned __int64 RN, _CONTEXT * pContext, _xDISPATCHER_CONTEXT * pDC), Line 306
000A4A2F   ntdll.dll!_chkstk+0x11F
00004CEF   ntdll.dll!RtlWalkFrameChain+0x14BF
00008AE6   ntdll.dll!RtlRaiseException+0x316
00039319   KERNELBASE.dll!RaiseException+0x69
0050339F   NetBox.dll!_CxxThrowException(void * pExceptionObject, const _s__ThrowInfo * pThrowInfo), Line 82
00060BE4   NetBox.dll!TTerminal::FatalError(Exception * E, const UnicodeString & AMsg, const UnicodeString & AHelpKeyword), Line 3067
00086F0C   NetBox.dll!TSecureShell::PuttyFatalError(const UnicodeString & AError), Line 1628
00124FAE   NetBox.dll!connection_fatal(Seat * seat, const char * message), Line 270
00242768   NetBox.dll!seat_connection_fatal(Seat * seat, const char * fmt, ...), Line 18
00216135   NetBox.dll!ssh_remote_error(Ssh * ssh, const char * fmt, ...), Line 483
0020FBAB   NetBox.dll!select_result(unsigned __int64 wParam, __int64 lParam), Line 1715
00084D06   NetBox.dll!TSecureShell::HandleNetworkEvents(unsigned __int64 Socket, _WSANETWORKEVENTS & Events), Line 2086
00085D09   NetBox.dll!TSecureShell::ProcessNetworkEvents(unsigned __int64 Socket), Line 2098
00082794   NetBox.dll!TSecureShell::EventSelectLoop::__l8::<lambda>(void), Line 2177
00081581   NetBox.dll!Sysutils::detail::scope_guard<void <lambda>(void),void <lambda>(void)>::scope_guard<void <lambda>(void),void <lambda>(void)>(TSecureShell::EventSelectLoop::__l8::void <lambda>(void) && f, TSecureShell::EventSelectLoop::__l8::void <lambda>(void) && f2), Line 479
0008104E   NetBox.dll!Sysutils::detail::make_try_finally<void <lambda>(void),void <lambda>(void)>(TSecureShell::EventSelectLoop::__l8::void <lambda>(void) && f, TSecureShell::EventSelectLoop::__l8::void <lambda>(void) && f2), Line 496
000841DE   NetBox.dll!TSecureShell::EventSelectLoop(unsigned int MSec, bool ReadEventRequired, _WSANETWORKEVENTS * Events), Line 2222
0008538E   NetBox.dll!TSecureShell::Idle(unsigned int MSec), Line 2272
00064501   NetBox.dll!TTerminal::Idle(void), Line 1368
001BF52D   NetBox.dll!TWinSCPFileSystem::ProcessPanelEventEx(__int64 Event, void * Param), Line 759
001AB71F   NetBox.dll!TCustomFarPlugin::ProcessSynchroEvent(const ProcessSynchroEventInfo * Info), Line 294
001970D6   NetBox.dll!ProcessSynchroEventW(const ProcessSynchroEventInfo * Info), Line 107

Apparently TTerminal::FatalError threw an exception and something else up the stack didn't manage to recover from it.

@michaellukashov @ssvine FYI (also please consider including a map file, users not always have PDBs)

[exkrexpexfex]

Have you tried the latest version? With your "so called" steps to reproduce, I do not have any issues. Maybe you need to share more details.

I believe the issue is environment-specific. I would be happy to provide more details if you could guide me on how to collect them.

[ssvine]

Can you download the latest Far build (it has the most recent NetBox) and try to reproduce the bug again?

I cannot reproduce the bug, so this information may help me:

• Have you changed any default parameters of the session (and the plugin itself)? Can you confirm that you are using SFTP protocol (not SCP)?
• What exactly did you do after the session was opened? You mentioned inactivity timeout, how long does it last?
• What kind of SSH server do you use? Maybe you know what non-default configuration parameters are used by the SSH server? In particular, if you use OpenSSH, I'm interested in the result of the following command sshd -T | grep -i alive.
• Does the bug occur constantly or occasionally?
• Do you use any proxy?
• You use quite old Windows version, do you have the opportunity to reproduce the bug on another machine?

[exkrexpexfex]

Can you download the latest Far build (it has the most recent NetBox) and try to reproduce the bug again?

Downloaded Nightly Build x64 archive from https://www.farmanager.com/download.php?l=en Is it latest?

• Have you changed any default parameters of the session (and the plugin itself)? Can you confirm that you are using SFTP protocol (not SCP)?

Nothing changed in default settings. I've added new SFTP session in NetBox of newly downloaded Far keeping "allow SCP fallback" checked by default

• What exactly did you do after the session was opened? You mentioned inactivity timeout, how long does it last?

After opening session I did a command "cd /opt", then switched to my other apps so that Far window stays in background. Waited for ~ 40 minutes and got the crash. VPN to the SSH server was disconnected and reconnected during this period. I've checked VPN reconnection without waiting - NetBox managed to recover connection with no crash.

• What kind of SSH server do you use? Maybe you know what non-default configuration parameters are used by the SSH server? In particular, if you use OpenSSH, I'm interested in the result of the following command sshd -T | grep -i alive.

Version: OpenSSH_8.0p1, OpenSSL 1.1.1k FIPS 25 Mar 2021

sshd -T | grep -I alive clientaliveinterval 300 clientalivecountmax 3 tcpkeepalive no

• Does the bug occur constantly or occasionally?

By now I've observed this on two different environments, different clients, different servers, different network arrangements. I can't say that it occurs every time I don't touch Far for some period, but still it crashed quite often.

• Do you use any proxy?

No SSH proxy, direct connection within same LAN for the initial bug report, connection over VPN this time

• You use quite old Windows version, do you have the opportunity to reproduce the bug on another machine?

Reproduced on newer Windows VM OS: Windows NT Workstation 10.0.22000, 0x300/0x65 (Windows 10 Home, version 21H2, OS build 22000.2538) @ssvine please check the new bug report bug_report 2.txt

[Px-x64]

Downloaded Nightly Build x64 archive from https://www.farmanager.com/download.php?l=en Is it latest?

It is latest, but for debug purposes it is better to take files from https://github.com/FarGroup/FarManager/releases, downloading both .7z (or .msi) file for Far itself, and .pdb.7z file for debug symbols, as now your report have

001F99C5   NetBox.dll!SetStartupInfoW+0x62795
00010C90   NetBox.dll!<unknown> (get the pdb)
0051305A   NetBox.dll!SetStartupInfoW+0x37BE2A
00508EA7   NetBox.dll!SetStartupInfoW+0x371C77
00503CC5   NetBox.dll!SetStartupInfoW+0x36CA95
00507E09   NetBox.dll!SetStartupInfoW+0x370BD9
00507F41   NetBox.dll!SetStartupInfoW+0x370D11
005046D5   NetBox.dll!SetStartupInfoW+0x36D4A5

Which is not useful without .pdb on your side or .dmp file from crash

[exkrexpexfex]

bug_report 3.txt Reproduced with PDBs @Px-x64 @ssvine have a look

[ssvine]

@exkrexpexfex, @Px-x64 thanks. I'll check soon.

[ssvine]

@exkrexpexfex, @Px-x64: NetBox 24.5.0.602 is ready, now you can test the fix.

[exkrexpexfex]

Looks good now. I didn't manage to reproduce the crash with the new NetBox version. @ssvine great work! Thank you