netdev - Re: [PATCH net-next] bridge: remove a redundant synchronize

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 04 Apr 2013 09:03:45 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Jiri Pirko <jiri@...nulli.us>
Cc:	David Miller <davem@...emloft.net>, vfalico@...hat.com,
	netdev@...r.kernel.org, stephen@...workplumber.org
Subject: Re: [PATCH net-next] bridge: remove a redundant synchronize_net()

On Thu, 2013-04-04 at 08:44 -0700, Eric Dumazet wrote:

> Because maybe the synchronize_net() in netdev_rx_handler_unregister()
> is enough and you dont even need the call_rcu(). Thats was my question.

So we have the following sequence in team_port_del()

        netdev_rx_handler_unregister(port_dev);

        netdev_upper_dev_unlink(port_dev, dev);
        team_port_disable_netpoll(port);
        vlan_vids_del_by_dev(port_dev, dev);
        dev_uc_unsync(port_dev, dev);
        dev_mc_unsync(port_dev, dev);
        dev_close(port_dev);
        team_port_leave(team, port);

        __team_option_inst_mark_removed_port(team, port);
        __team_options_change_check(team);
        __team_option_inst_del_port(team, port);
        __team_port_change_port_removed(port);

        team_port_set_orig_dev_addr(port);
        dev_set_mtu(port_dev, port->orig.mtu);
        synchronize_rcu();
        kfree(port);

And I suspect we can remove synchronize_rcu() call.

But as this is a long list of operations, maybe some of them requires
the rcu grace period before kfree(port)



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html