Re: linux has added "close on exec" flags to lots of fd calls

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Mon, Aug 04, 2008 at 01:25:26PM -0400, Steven M. Bellovin wrote:
> I do -- I've seen this failure fairly often, though not as much in
> recent years.  It was more common in the days before window systems
> (and especially before job control), when lots of programs had shell
> escapes.  Even adventure(6) had one.

(a) For multi-threaded programs, add a good implementation of the POSIX
spawn interface. It is a lot easier to use and can be at least as fast
as vfork + exec, if not faster.

(b) For non-threaded programs, sigprocmask is enough to fix the race.
Many programs should actually think about using closefrom or similiar
functions after fork.

Joerg