[PATCH] binder: fix test regression due to sender_euid change

[Todd Kjos]

On Fri, Nov 19, 2021 at 3:00 PM Paul Moore <paul at paul-moore.com> wrote:
>
> On Fri, Nov 12, 2021 at 1:07 PM Todd Kjos <tkjos at google.com> wrote:
> >
> > This is a partial revert of commit
> > 29bc22ac5e5b ("binder: use euid from cred instead of using task").
> > Setting sender_euid using proc->cred caused some Android system test
> > regressions that need further investigation. It is a partial
> > reversion because subsequent patches rely on proc->cred.
> >
> > Cc: stable at vger.kernel.org # 4.4+
> > Fixes: 29bc22ac5e5b ("binder: use euid from cred instead of using task")
> > Signed-off-by: Todd Kjos <tkjos at google.com>
> > Change-Id: I9b1769a3510fed250bb21859ef8beebabe034c66

Greg, I neglected to remove the "Change-Id" from my Android pre-submit
testing. Can you remove that, or would you like me to resubmit without
it?

> > ---
> > - the issue was introduced in 5.16-rc1, so please apply to 5.16
> > - this should apply cleanly to all stable branches back to 4.4
> >   that contain "binder: use euid from cred instead of using task"
> >
> >
> >  drivers/android/binder.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
>
> This looks okay to me.  I assume this is going in via GregKH's tree?
>
> Acked-by: Paul Moore <paul at paul-moore.com>
>
> > diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> > index 49fb74196d02..cffbe57a8e08 100644
> > --- a/drivers/android/binder.c
> > +++ b/drivers/android/binder.c
> > @@ -2710,7 +2710,7 @@ static void binder_transaction(struct binder_proc *proc,
> >                 t->from = thread;
> >         else
> >                 t->from = NULL;
> > -       t->sender_euid = proc->cred->euid;
> > +       t->sender_euid = task_euid(proc->tsk);
> >         t->to_proc = target_proc;
> >         t->to_thread = target_thread;
> >         t->code = tr->code;
> > --
> > 2.34.0.rc1.387.gb447b232ab-goog
>
> --
> paul moore
> www.paul-moore.com