httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Brian Behlendorf <br...@organic.com>
Subject Re: Core dump with 1.2b9-dev, gdb trace
Date Sat, 12 Apr 1997 22:02:15 GMT
On Sat, 12 Apr 1997, Ben Laurie wrote:
> > This with a version current as of April 8th, 1am.  Looks like the call to
> > get_remote_host returned something Apache didn't like - I am using bind 8.1 and
> > its resolver library.  
> > 
> > Program terminated with signal 6, Abort trap.
> > #0  0x60c89 in kill ()
> > (gdb) where
> > #0  0x60c89 in kill ()
> > #1  0x601e7 in abort ()
> > #2  0x2f90 in just_die ()
> > #3  <signal handler called>
> > #4  0x384b6 in __res_send (buf=0xefbf975c "69.164.137.207.in-addr.arpa",
> >     buflen=1, ans=0xc <Address 0xc out of bounds>, anssiz=-272657572)
> >     at res_send.c:589
> 
> This out-of-bounds address is supplied by the library routine, not by Apache.
> I'd have expected a static buffer, in which case it is hard to see how Apache
> stomped it. 

Oh right, it's not a proper system call, but a library call, one statically
linked with Apache, which is why a seg fault there could seg fault Apache even
though Apache's doing things fine.  This is experimental bind code after all.

> But it may be that it does something cleverer. Do you have the
> source of ho_byaddr in dns_ho.c?

Sure, it's attached.  If this is clearly a bind problem I'm not inclined to
worry much about it:

> Note that buflen and anssiz appear to be garbage as well as ans.

Note that gethostbyaddr was given something weird too.

> > #5  0x3fb15 in ho_byaddr (this=0x7e280, addr=0xb603c, len=4, af=2)
> >     at dns_ho.c:287
> > #6  0x39940 in ho_byaddr (this=0x7e400, addr=0xb603c, len=4, af=2)
> >     at gen_ho.c:168
> > #7  0x35ebe in gethostbyaddr (addr=0xb603c "O\211$E", len=4, af=2)
> >     at gethostent.c:118
> > #8  0x4ebf in get_remote_host ()

	Brian

--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--
brian@organic.com  www.apache.org  hyperreal.com  http://www.organic.com/JOBS

Mime
View raw message