From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [PATCH] net: correct error path in rtnl_newlink() Date: Tue, 11 Feb 2014 15:51:30 -0800 Message-ID: <1392162690-6647-3-git-send-email-xiyou.wangcong@gmail.com> References: <1392162690-6647-1-git-send-email-xiyou.wangcong@gmail.com> Cc: Cong Wang , "David S. Miller" , Eric Dumazet , Cong Wang To: netdev@vger.kernel.org Return-path: Received: from mail-pb0-f54.google.com ([209.85.160.54]:59630 "EHLO mail-pb0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752456AbaBKXvp (ORCPT ); Tue, 11 Feb 2014 18:51:45 -0500 Received: by mail-pb0-f54.google.com with SMTP id uo5so8433337pbc.13 for ; Tue, 11 Feb 2014 15:51:44 -0800 (PST) In-Reply-To: <1392162690-6647-1-git-send-email-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Cong Wang I saw the following BUG when ->newlink() fails in rtnl_newlink(): [ 40.240058] kernel BUG at net/core/dev.c:6438! this is due to free_netdev() is not supposed to be called before netdev is completely unregistered, therefore it is not correct to call free_netdev() here, at least for ops->newlink!=NULL case, many drivers call it in ->destructor so that rtnl_unlock() will take care of it, we probably don't need to do anything here. Cc: David S. Miller Cc: Eric Dumazet Signed-off-by: Cong Wang Signed-off-by: Cong Wang --- net/core/rtnetlink.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 048dc8d..1a0dac2 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1963,16 +1963,21 @@ replay: dev->ifindex = ifm->ifi_index; - if (ops->newlink) + if (ops->newlink) { err = ops->newlink(net, dev, tb, data); - else + /* Drivers should call free_netdev() in ->destructor + * and unregister it on failure so that device could be + * finally freed in rtnl_unlock. + */ + if (err < 0) + goto out; + } else { err = register_netdevice(dev); - - if (err < 0) { - free_netdev(dev); - goto out; + if (err < 0) { + free_netdev(dev); + goto out; + } } - err = rtnl_configure_link(dev, ifm); if (err < 0) unregister_netdevice(dev); -- 1.8.3.1