Re: exec server and /dev/fd/N

[Carl Fredrik Hammar]

On Wed, May 26, 2010 at 01:39:24AM +0200, Emilio Pozuelo Monfort wrote:
> On 25/05/10 21:10, Carl Fredrik Hammar wrote:
> >> @@ -278,7 +280,9 @@ check_hashbang (struct execdata *e,
> >>          else
> >>            name = argv;
> >>  
> >> -        if (strchr (name, '/') != NULL)
> >> +        if (filename)
> >> +          error = lookup (name = filename, 0, &name_file);
> >> +        else if (strchr (name, '/') != NULL)
> >>            error = lookup (name, 0, &name_file);
> >>          else if ((error = hurd_catch_signal
> >>                    (sigmask (SIGBUS) | sigmask (SIGSEGV),
> > 
> > Should check for "" instead of null.
> 
> Shouldn't I check both to avoid somebody using the RPC directly and sending 
> NULL
> in filename to crash the exec server and cause a DoS?  (-:

You can't actually send NULL if it's a string_t since it is a fixed-size array,
but I guess it wouldn't hurt.

Regards,
  Fredrik