bridge: offload bridge port attributes to switch asic if feature flag set

Hello Roopa Prabhu,

This is a semi-automatic email about new static checker warnings.

The patch 68e331c785b8: "bridge: offload bridge port attributes to switch asic if feature flag set" from Jan 29, 2015, leads to the following Smatch complaint:

net/bridge/br_netlink.c:552 br_setlink()
error: we previously assumed 'p' could be null (see line 518)

net/bridge/br_netlink.c
517

   518		if (p && protinfo) {
                    ^

Check for NULL.

519 if (protinfo->nla_type & NLA_F_NESTED) {
520 err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
521 protinfo, br_port_policy);
522 if (err)
523 return err;
524
525 spin_lock_bh(&p->br->lock);
526 err = br_setport(p, tb);
527 spin_unlock_bh(&p->br->lock);
528 } else {
529 /* Binary compatibility with old RSTP */
530 if (nla_len(protinfo) < sizeof(u8))
531 return -EINVAL;
532
533 spin_lock_bh(&p->br->lock);
534 err = br_set_port_state(p, nla_get_u8(protinfo));
535 spin_unlock_bh(&p->br->lock);
536 }
537 if (err)
538 goto out;
539 }
540
541 if (afspec) {
542 err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
543 afspec, RTM_SETLINK);
544 }
545
546 if (!(flags & BRIDGE_FLAGS_SELF)) {
547 /* set bridge attributes in hardware if supported
548 */
549 ret_offload = netdev_switch_port_bridge_setlink(dev, nlh,
550 flags);
551 if (ret_offload && ret_offload != -EOPNOTSUPP)
552 br_warn(p->br, "error setting attrs on port %u(%s)\n",

                                        ^^^^^

New dererference.

   553					(unsigned int)p->port_no, p->dev->name);
   554		}

Also:

	net/bridge/br_netlink.c:592 br_dellink()
	error: we previously assumed 'p' could be null (see line 575)

regards,
dan carpenter

Thanks, yes, looks like i don't address the case where the message comes in on the bridge device. I will post a patch a patch soon.