Re: [PATCH net] net: bridge: fix early call to br_stp_change_bridge_id

On 12/18/2017 04:22 PM, Nikolay Aleksandrov wrote:

On 12/18/2017 04:24 AM, Toshiaki Makita wrote:

quoted

On 2017/12/16 20:31, Nikolay Aleksandrov wrote:

[snip]

quoted

...

quoted

 	err = br_changelink(dev, tb, data, extack);
-	if (err)
+	if (err) {
+		/* clean possible fdbs from br_stp_change_bridge_id above */
+		br_fdb_delete_by_port(br, NULL, 0, 1);

Don't we need to call br_dev_delete (br_link_ops.dellink) after
successful register instead of br_fdb_delete?
Particularly I'm wondering if not calling br_sysfs_delbr() is ok or not.

Funny, that is actually the only reason we need to call it (br_sysfs_delbr). :-)

Good catch, that is another leak - the bridge sysfs entries are registered when
NETDEV_REGISTER event happens (register_netdevice) but are not properly cleaned up
on error there. This has also been present since the introduction of changelink
during newlink, commit:
 b6677449dff6 ("bridge: netlink: call br_changelink() during br_dev_newlink()")

err, since the changelink was fixed to be after device registration in commit:
 5b8d5429daa0 ("bridge: netlink: register netdevice before executing changelink")

I'll send v2 that does br_dev_delete(dev, NULL) instead of the current cleanup.
With kobject debug enabled and that I can see "brif" and the rest of the sysfs
files getting freed properly, while before they weren't.

Thanks,
 Nik