Re: [PATCH 1/3] treewide: Add SOCK_CLOEXEC to accept() calls that are missing it

[Stefano Brivio <sbrivio@redhat.com>]

On Mon, 18 May 2026 12:28:57 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Sat, May 16, 2026 at 05:46:11PM +0200, Stefano Brivio wrote:
> > On Wed, 13 May 2026 14:14:21 +1000
> > David Gibson <david@gibson.dropbear.id.au> wrote:
> >   
> > > Generally we try to set the O_CLOEXEC flag on every fd we create.  This
> > > seems to be generally accepted security best practice these days, and we
> > > never fork(), so certainly have no need to pass fds to children.  
> > 
> > But we do clone() with CLONE_FILES (even though when we clone() to call
> > execvp() later, we don't set CLONE_FILES), so, even though I don't see
> > a reason to skip O_CLOEXEC for c->fd_tap, this conclusion shouldn't be
> > automatic from the fact we don't fork().  
> 
> So, I did think about that when  wrote it, but went for the short
> version rather than saying clone() with CLONE_FILES doesn't count.
> 
> Now, I realised that we've both fallen for the trap again, forgetting
> that this has nothing to do with fork() or clone() and is, as it says
> right there in the name, about exec().

No, wait, I didn't fall for it, not this time. :) That's why I was
mentioning that when we call clone() and execvp() later (which would be
the only path that matters), we don't set CLONE_FILES anyway.

-- 
Stefano