On Tue, Sep 22, 2020 at 04:08:16PM +0200, Why 42? The lists account. wrote:
>
> On Tue, Sep 22, 2020 at 07:12:47AM -0000, Stuart Henderson wrote:
> > Sounds like they are trapping sigbus themselves but the handler isn't
> > giving useful information.
> >
> > Try just running it under gdb:
> > pkg_add gdb
> > egdb ods-signerd
> > set args -dv
> > run
> >
> > and see if you can get a backtrace. You may need to build opendnssec
> > with debug symbols to get a usable trace though (checkout the ports
> > tree and build it with "make DEBUG=-g repackage reinstall").
>
> Hi Stuart,
>
> Thanks for that, concise and really helpful. The debug build process was
> easier than I expected :).
>
> For what is worth the results in egdb are:
> Thread 2 received signal SIGBUS, Bus error.
> [Switching to thread 478985]
> 0x00000851fb90f5f5 in ldns_rr_clone () from /usr/local/lib/libldns.so.7.1
> (gdb) bt
> #0 0x00000851fb90f5f5 in ldns_rr_clone () from /usr/local/lib/libldns.so.7.1
> #1 0x0000084fca6e4e55 in ixfr_del_rr (ixfr=0x852782d0d80,
> rr=0xdfdfdfdfdfdfdfdf) at signer/ixfr.c:134
this is a use after free
^^^^^^^^^^^^^^^^
> #2 0x0000084fca6ea0da in rrset_sign (ctx=0x8522842d800, rrset=<optimized
> out>, signtime=1600781131) at signer/rrset.c:758
> #3 0x0000084fca6ddd6c in drudge (worker=0x8521a9e4000) at
> daemon/signertasks.c:196
> #4 0x0000084fca714e0b in runthread (data=0x851d1fc6300) at janitor.c:318
> #5 0x00000852553ad0d1 in _rthread_start (v=<optimized out>) at
> /usr/src/lib/librthread/rthread.c:96
> #6 0x00000851f742dc38 in __tfork_thread () at
> /usr/src/lib/libc/arch/amd64/sys/tfork_thread.S:77
> #7 0x0000000000000000 in ?? ()
> (gdb) info args
> No symbol table info available.
> (gdb) info local
> No symbol table info available.
> (gdb) up
> #1 0x0000084fca6e4e55 in ixfr_del_rr (ixfr=0x852782d0d80,
> rr=0xdfdfdfdfdfdfdfdf) at signer/ixfr.c:134
> 134 ldns_rr* rr_copy = ldns_rr_clone(rr);
> (gdb) info args
> ixfr = 0x852782d0d80
> rr = 0xdfdfdfdfdfdfdfdf
> (gdb) info local
> rr_copy = <optimized out>
>
> I'm not a gdb expert, but I wonder why it says "No symbol table info
> available" ...
>
> In any case, I've forwarded the info. on to the opendnssec developer
> list.
>
> Thanks again.
>
> Cheers,
> Robb.
>
--
I'm not entirely sure you are real.
