Crash after bad file descriptor

[mirh]

So, I was testing my atrociously flippant powerline connection.. only to realize after half an hour of increasingly puzzled attempts, that I had started to constantly get closed connection errors not due to network conditions but just because the server had crashed. This was on the fateful last client run:

iperf3: error - unable to send control message - port may not be available, the other side may have stopped running, etc.: Connection reset by peer

And this was on the server (note this was the default parameters, and there likely was 4 dozens transfer runs instead of just 10 because the network was indeed on the slow and shaky side of things)

-----------------------------------------------------------
Server listening on 5201 (test #81)
-----------------------------------------------------------
Accepted connection from 192.168.1.49, port 53742
[  5] local 192.168.1.3 port 5201 connected to 192.168.1.49 port 53743
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  0.00 Bytes  0.00 bits/sec
[  5]   1.00-2.00   sec   128 KBytes  1.05 Mbits/sec
[  5]   2.00-3.00   sec   128 KBytes  1.05 Mbits/sec
[  5]   3.00-4.00   sec   384 KBytes  3.14 Mbits/sec
[  5]   4.00-5.00   sec   512 KBytes  4.20 Mbits/sec
[  5]   5.00-6.00   sec   384 KBytes  3.15 Mbits/sec
[  5]   6.00-7.00   sec   256 KBytes  2.10 Mbits/sec
[  5]   7.00-8.00   sec  0.00 Bytes  0.00 bits/sec
[  5]   8.00-9.00   sec  0.00 Bytes  0.00 bits/sec
[  5]   9.00-10.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  10.00-11.00  sec   128 KBytes  1.05 Mbits/sec
[  5]  11.00-12.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  12.00-13.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  13.00-14.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  14.00-15.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  15.00-16.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  16.00-17.00  sec   128 KBytes  1.05 Mbits/sec
[  5]  17.00-18.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  18.00-19.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  19.00-20.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  20.00-21.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  21.00-22.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  22.00-23.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  23.00-24.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  24.00-25.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  25.00-26.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  26.00-27.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  27.00-28.00  sec  10.9 KBytes  88.9 Kbits/sec
[  5]  28.00-29.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  29.00-30.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  30.00-31.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  31.00-32.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  32.00-33.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  33.00-34.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  34.00-35.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  35.00-36.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  36.00-37.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  37.00-38.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  38.00-39.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  39.00-40.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  40.00-41.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  41.00-42.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  42.00-43.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  43.00-44.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  44.00-45.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  45.00-46.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  46.00-47.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  47.00-48.00  sec  0.00 Bytes  0.00 bits/sec
[  5]  48.00-49.00  sec  0.00 Bytes  0.00 bits/sec
iperf3: error - select failed: Bad file descriptor
-----------------------------------------------------------
Server listening on 5201 (test #82)
-----------------------------------------------------------
      0 [iperf3] iperf3 94 cygwin_exception::open_stackdumpfile: Dumping stack trace to iperf3.exe.stackdump

Now, if you search for that error upstream there are actually quite the number of reports, and even some hopeful tangent solution.
But nowhere in there I could notice mentions of fully fledged crashes like this:

Exception: STATUS_ACCESS_VIOLATION at rip=000100402CB6
rax=0000000000000000 rbx=0000000A00033F60 rcx=0000000A00033F70
rdx=0000000000000000 rsi=0000000A00016D20 rdi=00000007FFE00000
r8 =000000000000000A r9 =000000007FFE4000 r10=00000007FFE00000
r11=0000000100412BC8 r12=0000000A00034840 r13=0000000A000348F0
r14=0000000800022EC0 r15=0000000000000000
rbp=0000000000000000 rsp=00000007FFDFCCB0
program=C:\folder\iperf3.exe, pid 94, thread iperf3
cs=0033 ds=002B es=002B fs=0053 gs=002B ss=002B
Stack trace:
Frame         Function      Args
000000000000  000100402CB6 (000000003000, 000A00034840, 00000063CC60, 00000063CC60) iperf3.exe+0x2CB6
000000000000  00010040E645 (000000000000, 000000000000, 000000000000, 000000000000) iperf3.exe+0xE645
000000000000  7FFD50386D6F (000000600000, 00000063CC60, 000000003000, 000000000000) cygwin1.dll+0x66D6F
000000000000  7FFD503244AA (000000600000, 00000063CC60, 000000003000, 000000000000) cygwin1.dll+0x44AA
End of stack trace
Loaded modules:
000100400000 iperf3.exe
7FFDA1AF0000 ntdll.dll
7FFDA06E0000 KERNEL32.DLL
7FFD9F7B0000 KERNELBASE.dll
7FFD50320000 cygwin1.dll
7FFDA04A0000 advapi32.dll
7FFDA11C0000 msvcrt.dll
7FFDA1120000 sechost.dll
7FFDA0FF0000 RPCRT4.dll
7FFD9F620000 bcrypt.dll
7FFD9EA50000 CRYPTBASE.DLL
7FFD9F490000 bcryptPrimitives.dll
7FFD84BC0000 netapi32.dll
7FFD94F00000 SAMCLI.DLL
7FFD9F520000 ucrtbase.dll
7FFD9AB30000 SAMLIB.dll
7FFD9E650000 NETUTILS.DLL
7FFD9FFD0000 user32.dll
7FFD9F2C0000 win32u.dll
7FFDA0410000 GDI32.dll
7FFD9F1A0000 gdi32full.dll
7FFD9F3F0000 msvcp_win.dll
7FFDA02A0000 IMM32.DLL
7FFDA03A0000 ws2_32.dll
7FFD9E860000 mswsock.dll

[ar51an]

Are you using the same version on both machines?
Similar issue has been reported for other OS.

esnet/iperf#653
esnet/iperf#753
esnet/iperf#859
esnet/iperf#1233

Open this issue in the below source repo for better support:
https://github.com/esnet/iperf

[mirh]

I had seen them, yes, but I was under the impression that "failure" and "errors" there were not implying a crash to have happened.
Version 3.16 was used in both machines.