510.1346 crashdump

ID:2165570
 
Oct 28 2016, 5:22 pm
BYOND Version:510
Operating System:Linux
Web Browser:Firefox 49.0
Applies to:Dream Daemon
Status: Open
Issue hasn't been assigned a status value.
#0  0xf6d3d06d in _IO_default_xsputn () from /lib32/libc.so.6
#1  0xf6d103e4 in vfprintf () from /lib32/libc.so.6
#2  0xf6d327a2 in vsprintf () from /lib32/libc.so.6
#3  0xf6d19d0f in sprintf () from /lib32/libc.so.6
#4  0xf607a25e in ?? () from /lib32/libresolv.so.2
#5  0xf607a7b7 in __libc_res_nsearch () from /lib32/libresolv.so.2
#6  0xf6ffd1b5 in _nss_dns_gethostbyname3_r () from /lib32/libnss_dns.so.2
#7  0xf6ffd51a in _nss_dns_gethostbyname_r () from /lib32/libnss_dns.so.2
#8  0xf6dcadbb in gethostbyname_r () from /lib32/libc.so.6
#9  0xf6dca57c in gethostbyname () from /lib32/libc.so.6
#10 0xf7510ee0 in SocketLib::GetSocketAddress(char const*, char const*, void (*)(sockaddr_in*, void*), void*) () from /home/ss13/byond/bin/libbyond.so
#11 0xf750bc49 in ?? () from /home/ss13/byond/bin/libbyond.so
#12 0xf74f9acc in ?? () from /home/ss13/byond/bin/libbyond.so
#13 0xf75052b5 in ?? () from /home/ss13/byond/bin/libbyond.so
#14 0xf750ecb0 in ?? () from /home/ss13/byond/bin/libbyond.so 


From        To          Syms Read   Shared Object Library
                        No          linux-gate.so.1
0xf72eff50  0xf768db88  Yes (*)     /home/ss13/byond/bin/libbyond.so
0xf701f460  0xf7094c48  Yes (*)     /home/ss13/byond/bin/libext.so
0xf6fed9b0  0xf6ff0eaa  Yes (*)     /lib32/librt.so.1
0xf6f409f0  0xf6faeccd  Yes (*)     /usr/lib32/libstdc++.so.6
0xf6eb8600  0xf6ee5f65  Yes (*)     /lib32/libm.so.6
0xf6e980a0  0xf6eadf45  Yes (*)     /usr/lib32/libgcc_s.so.1
0xf6e7e870  0xf6e8af97  Yes         /lib32/libpthread.so.0
0xf6ce4420  0xf6e1470e  Yes (*)     /lib32/libc.so.6
0xf6cc8ad0  0xf6cc996c  Yes (*)     /lib32/libdl.so.2
0xf775d860  0xf777570c  Yes (*)     /lib/ld-linux.so.2
0xf6cbce70  0xf6cc18a5  Yes (*)     /lib32/libnss_compat.so.2
0xf6ca61d0  0xf6cb2723  Yes (*)     /lib32/libnsl.so.1
0xf6c989e0  0xf6c9ee0a  Yes (*)     /lib32/libnss_nis.so.2
0xf6c8bad0  0xf6c928ab  Yes (*)     /lib32/libnss_files.so.2
0xf6ffbc40  0xf6ffeb9e  Yes (*)     /lib32/libnss_dns.so.2
0xf6075720  0xf6081db4  Yes (*)     /lib32/libresolv.so.2

I have the actual GDB coredump available to download if it'd be useful.
Oct 28 2016, 8:54 pm
If I'm reading this correctly, the crash is not happening in BYOND code but in gethostbyname(). I'm not sure this is strictly a BYOND bug.

If you trace back in the core, do you have any info on what arguments were passed to gethostbyname()? It seems the answer would lie with those.
Oct 28 2016, 8:54 pm
Oh good point, I'll get back to you.
Oct 29 2016, 11:10 am
Ok, well, GDB is deciding to be absolutely terrible (to noones surprise) so I won't be able to get you the arguments. The issue is related to world.Export, which means the issue was probably fixed in 511 (we can't update to that until the stringtable issue is fixed.)
Oct 29 2016, 3:20 pm
What string table issue are you referring to again? I'm not aware of anything with strings that's specific to 511.
Oct 29 2016, 3:20 pm
http://www.byond.com/forum/?post=2165231
Really hard to debug and happens on server restart for us.
Oct 29 2016, 3:32 pm
If it happens all the time on restart I can take a look if you have source.

What I'm looking at in the code says this should be impossible unless something has corrupted a part of global memory, or unless your string tree has a serious balance problem on load.
Oct 29 2016, 4:32 pm
THIS issue is unrelated to the other one, it occurs every now and again and is definitely linked to world.Export (bad host parsing perhaps?)
Oct 30 2016, 12:35 am
I can't see that other forum thread?
Oct 30 2016, 5:30 am
It's tagged as a security/exploit issue due to certain information potentially revealing parts of our (closed source) codebase.