binder: fix atomic sleep when get extended error

binder_inner_proc_lock(thread->proc) is a spin lock, copy_to_user can't
be called with in this lock.

Copy it as a local variable to fix it.

Fixes: bd32889e841c ("binder: add BINDER_GET_EXTENDED_ERROR ioctl")
Reported-by: syzbot+46fff6434a7f968ecb39@syzkaller.appspotmail.com
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Schspa Shi <schspa@gmail.com>
Link: https://lore.kernel.org/r/20220518011754.49348-1-schspa@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I1de3962ef9b29208c97df6379d5bc46942accef1

drivers/android/binder.c

@@ -5168,19 +5168,16 @@ static int binder_ioctl_get_freezer_info(
 static int binder_ioctl_get_extended_error(struct binder_thread *thread,
 					   void __user *ubuf)
 {
-	struct binder_extended_error *ee = &thread->ee;
+	struct binder_extended_error ee;
 
 	binder_inner_proc_lock(thread->proc);
-	if (copy_to_user(ubuf, ee, sizeof(*ee))) {
-		binder_inner_proc_unlock(thread->proc);
-		return -EFAULT;
-	}
-
-	ee->id = 0;
-	ee->command = BR_OK;
-	ee->param = 0;
+	ee = thread->ee;
+	binder_set_extended_error(&thread->ee, 0, BR_OK, 0);
 	binder_inner_proc_unlock(thread->proc);
 
+	if (copy_to_user(ubuf, &ee, sizeof(ee)))
+		return -EFAULT;
+
 	return 0;
 }