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

[Paul Moore]

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
> ---
> - 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