Hello Luiz Augusto von Dentz,
The patch 81be03e026dc: "Bluetooth: RFCOMM: Replace use of
memcpy_from_msg with bt_skb_sendmmsg" from Sep 3, 2021, leads to the
following
Smatch static checker warning:
net/bluetooth/rfcomm/sock.c:587 rfcomm_sock_sendmsg()
warn: passing zero to 'PTR_ERR'
net/bluetooth/rfcomm/sock.c
556 static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
557 size_t len)
558 {
559 struct sock *sk = sock->sk;
560 struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
561 struct sk_buff *skb;
562 int sent;
563
564 if (test_bit(RFCOMM_DEFER_SETUP, &d->flags))
565 return -ENOTCONN;
566
567 if (msg->msg_flags & MSG_OOB)
568 return -EOPNOTSUPP;
569
570 if (sk->sk_shutdown & SEND_SHUTDOWN)
571 return -EPIPE;
572
573 BT_DBG("sock %p, sk %p", sock, sk);
574
575 lock_sock(sk);
576
577 sent = bt_sock_wait_ready(sk, msg->msg_flags);
578
579 release_sock(sk);
580
581 if (sent)
582 return sent;
583
584 skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
585 RFCOMM_SKB_TAIL_RESERVE);
586 if (IS_ERR_OR_NULL(skb))
When a function returns both error pointers and NULL then that means
the feature is optional and can be turned off by the user.
blinking_lights = get_blinking_lights();
We should report the error to the user.
if (IS_ERR(blinking_lights))
return PTR_ERR(blinking_lights);
However, some users maybe want a smaller kernel with no blinking lights
so they disable it. In that case the driver has to check for NULL, and
not print an error message but instead continue as best as possible
without that feature enabled.
The bt_skb_sendmmsg() cannot return NULL. But if it did return NULL
then PTR_ERR(NULL) is success so that's not right... All the callers
of bt_skb_sendmmsg() have the same issue.
--> 587 return PTR_ERR(skb);
588
589 sent = rfcomm_dlc_send(d, skb);
590 if (sent < 0)
591 kfree_skb(skb);
592
593 return sent;
594 }
regards,
dan carpenter
