Re: Sending escape sequences to xterms via wall/talk

[a.beckett () fml co uk (Andrew Beckett)]

In article AA15592@iridium, "Christopher A. Stewart" <stewart () networx com> () writes:
> > > > > > "Mike" == Mike Raffety <mike_raffety () il us swissbank com> writes:
>
>     Mike> setuid programs don't produce core dumps; it's a security
>     Mike> feature.
>
> Huh? What *NIX are you using? I've not noticed that behavior..

I must admit I hadn't noticed that, so I thought I'd try it. Use the
following program (the numbers were randomly selected by hitting several
number keys at once):

/* dump_core.c */
main()
{
    long *i=(long *)3249243;

    while(1) {
        *i=(long) i;
        i+=349;
        }
}

compile this, and when you run it it will core dump (providing you have unlimited
core). If you setuid to root and run it as someone other than root, it just
does a bus error and doesn't core dump!

I'm running SunOS 4.1.3_U1.

So it looks as if Mike Raffety has a point!

Andrew.

P.S. I just looked at the man page for core (5). To quote from it:

     The operating system writes out a memory  image  of  a  ter-
     minated  process  when  any  of  various  errors occur.  See
     sigvec(2) for the list  of  reasons;  the  most  common  are
     memory  violations,  illegal  instructions,  bus errors, and
     user-generated quit signals.  The  memory  image  is  called
     core and is written in the process's working directory (pro-
     vided it can be; normal access controls apply).  Set-user-ID
     and  set-group-ID  programs  do  not produce core files when
     they terminate as this would cause a security loophole.


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