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From Ben Laurie <...@gonzo.ben.algroup.co.uk>
Subject Re: Core dump with 1.2b9-dev, gdb trace
Date Sat, 12 Apr 1997 22:34:16 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.

I thought that at first. But it isn't - it's been given an IP address. Dumping
it as ASCII wasn't so smart, though...

Cheers,

Ben.

> 
> > > #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 ()

-- 
Ben Laurie                Phone: +44 (181) 994 6435  Email: ben@algroup.co.uk
Freelance Consultant and  Fax:   +44 (181) 994 6472
Technical Director        URL: http://www.algroup.co.uk/Apache-SSL
A.L. Digital Ltd,         Apache Group member (http://www.apache.org)
London, England.          Apache-SSL author

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