[PATCH 5.4 09/92] binder: fix test regression due to sender_euid change

[Greg Kroah-Hartman]

From: Todd Kjos <tkjos@xxxxxxxxxx>

commit c21a80ca0684ec2910344d72556c816cb8940c01 upstream.

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.

Fixes: 29bc22ac5e5b ("binder: use euid from cred instead of using task")
Cc: stable@xxxxxxxxxxxxxxx # 4.4+
Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Signed-off-by: Todd Kjos <tkjos@xxxxxxxxxx>
Change-Id: I9b1769a3510fed250bb21859ef8beebabe034c66
Link: https://lore.kernel.org/r/20211112180720.2858135-1-tkjos@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/android/binder.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3095,7 +3095,7 @@ static void binder_transaction(struct bi
 		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;