Re: [fs/exec] 80bd5afdd8: xfstests.generic.633.fail

[Christian Brauner]

On Mon, Jan 31, 2022 at 02:49:36PM -0800, Kees Cook wrote:
> On Mon, Jan 31, 2022 at 01:59:40PM -0800, Andrew Morton wrote:
> > On Mon, 31 Jan 2022 18:13:44 +0100 Christian Brauner <brauner@xxxxxxxxxx> wrote:
> > 
> > > > in other words, the changes that you see CMD_ARGS[0] == NULL for
> > > > execveat() seem higher than for path-based exec.
> > > > 
> > > > To counter that we should probably at least update the execveat()
> > > > manpage with a recommendation what CMD_ARGS[0] should be set to if it
> > > > isn't allowed to be set to NULL anymore. This is why was asking what
> > > > argv[0] is supposed to be if the binary doesn't take any arguments.
> > > 
> > > Sent a fix to our fstests now replacing the argv[0] as NULL with "".
> > 
> > As we hit this check so quickly, I'm thinking that Ariadne's patch
> > "fs/exec: require argv[0] presence in do_execveat_common()" (which
> > added the check) isn't something we'll be able to merge into mainline?
> 
> I think the next best would be to mutate an NULL argv into { "", NULL }.
> However, I still think we should do the pr_warn().
> 
> Thoughts?

+1