Re: NSD exit status 11 on 7.0

On 2021-10-15, Peter J. Philipp <pjp@delphinusdns.org> wrote:
> On Fri, Oct 15, 2021 at 08:05:08PM +0200, Otto Moerbeek wrote:
> [ some cut ]
>
>> > Anything else I can collect.
>>
>> You might want to compile and install nsd wit debug symbols info:
>>
>> cd /usr/src/usr.sbin/nsd
>> make -f Makefile.bsd-wrapper obj
>> make -f Makefile.bsd-wrapper clean
>> DEBUG=-g make -f Makefile.bsd-wrapper
>> make -f Makefile.bsd-wrapper install
>>
>>
>> Then: collect a gdb trace from a running process: install gdb from ports,
>> run
>> egdb --pid=pidofnsdchild /usr/sbin/nsd
>>
>> and wait for the crash.
>>
>> But I'm mostly unfamiliar with the nsd code and what has been changed
>> recently. I's say make sure sthen@ and florian@ see this: move to
>> bugs@ as I do not know if they read misc@.
>>
>> -Otto
>
> Hi Otto and Mischa,
>
> I'm watching this unfold and I'm trying to convert this packet with tr and
> sed but I'm having a hard time, getting this to 101 bytes. It would be cool
> if you could show this packet in a hex dump ie. kdump -X or kdump -x.
>
> If you feel this really is a packet of nsd-death then I'd be interested in
> seeing the hexdump privately. I know how to read some DNS formats but the
> way it is in the kdump I'm having trouble converting that.
>
> Best Regards,
> -peter
>
>> >
>> > Mischa
>> >
>> >
>> > >
>> > > -Otto
>> > >
>> > > > 91127 nsd CALL
>> > > > recvfrom(7,0xb2ac85b8000,0x20109,0,0xb2acfa96018,0xb27e485a968)
>> > > > 91127 nsd GIO fd 7 read 101 bytes
>> > > > "By\0\0\0\^A\0\0\0\0\0\^A\^A6\^A0\^A1\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A1\^A0\^A0\^A0\^A4\^A0\^A0\^A1\^A0\^A0\^A0\^A6\^A3\^A0\^Aa\^A2\^Cip6\^Darpa\0\0\f\0\
>> > > > \^A\0\0)\^E\M-,\0\0\M^@\0\0\0"
>> > > > 91127 nsd STRU struct sockaddr { AF_INET,
>> > > > 141.101.75.185:10029 }
>> > > > 91127 nsd RET recvfrom 101/0x65
>> > > > 91127 nsd PSIG SIGSEGV SIG_DFL code SEGV_MAPERR<1> addr=0x10
>> > > > trapno=6
>> > > > 36104 nsd STRU struct pollfd [2] { fd=16, events=0x1<POLLIN>,
>> > > > revents=0<> } { fd=15, events=0x1<POLLIN>, revents=0<> }
>> > > > 36104 nsd PSIG SIGCHLD caught handler=0xb27e47fa340 mask=0<>
>>
>
>

$ echo 'By\0\0\0\^A\0\0\0\0\0\^A\^A6\^A0\^A1\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A1\^A0\^A0\^A0\^A4\^A\^A\0\0)\^E\M-,\0\0\M^@\0\0\0' | unvis | hexdump -C
00000000 42 79 00 00 00 01 00 00 00 00 00 01 01 36 01 30 |By...........6.0|
00000010 01 31 01 30 01 30 01 30 01 30 01 30 01 30 01 30 |.1.0.0.0.0.0.0.0|
00000020 01 30 01 30 01 30 01 30 01 30 01 30 01 31 01 30 |.0.0.0.0.0.0.1.0|
00000030 01 30 01 30 01 34 01 01 00 00 29 05 ac 00 00 80 |.0.0.4....).....|
00000040 00 00 00 0a |....|
00000044


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