Re: [PATCH] exec: fix the racy usage of fs_struct->in_exec

[Oleg Nesterov]

On 03/25, Mateusz Guzik wrote:
>
> On Tue, Mar 25, 2025 at 11:10 AM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> >
> > On 03/24, Mateusz Guzik wrote:
> > >
> > > On Mon, Mar 24, 2025 at 7:28 PM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> > > >
> > > > So to me it would be better to have the trivial fix for stable,
> > > > exactly because it is trivially backportable. Then cleanup/simplify
> > > > this logic on top of it.
> > >
> > > So I got myself a crap testcase with a CLONE_FS'ed task which can
> > > execve and sanity-checked that suid is indeed not honored as expected.
> >
> > So you mean my patch can't fix the problem?
>
> No, I think the patch works.
>
> I am saying the current scheme is avoidably hard to reason about.

Ah, OK, thanks. Then I still think it makes more sense to do the
cleanups you propose on top of this fix.

But I leave this to you and other fs/ maintainers.

Oleg.