From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladislav Yasevich Subject: [PATCH] vlan: Correctly propagate promisc|allmulti flags in notifier. Date: Tue, 12 May 2015 20:53:14 -0400 Message-ID: <1431478394-8257-1-git-send-email-vyasevic@redhat.com> Cc: kaber@trash.net, Vladislav Yasevich To: netdev@vger.kernel.org Return-path: Received: from mail-qc0-f175.google.com ([209.85.216.175]:34132 "EHLO mail-qc0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933877AbbEMAxY (ORCPT ); Tue, 12 May 2015 20:53:24 -0400 Received: by qcyk17 with SMTP id k17so14612205qcy.1 for ; Tue, 12 May 2015 17:53:23 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Currently vlan notifier handler will try to update all vlans for a device when that device comes up. A problem occurs, however, when the vlan device was set to promiscuous, but not by the user (ex: a bridge). In that case, dev->gflags are not updated. What results is that the lower device ends up with an extra promiscuity count. Here are the backtraces that prove this: [62852.052179] [] __dev_set_promiscuity+0x38/0x1e0 [62852.052186] [] ? _raw_spin_unlock_bh+0x1b/0x40 [62852.052188] [] ? dev_set_rx_mode+0x2e/0x40 [62852.052190] [] dev_set_promiscuity+0x24/0x50 [62852.052194] [] vlan_dev_open+0xd5/0x1f0 [8021q] [62852.052196] [] __dev_open+0xbf/0x140 [62852.052198] [] __dev_change_flags+0x9d/0x170 [62852.052200] [] dev_change_flags+0x29/0x60 The above comes from the setting the vlan device to IFF_UP state. [62852.053569] [] __dev_set_promiscuity+0x38/0x1e0 [62852.053571] [] ? vlan_dev_set_rx_mode+0x2b/0x30 [8021q] [62852.053573] [] __dev_change_flags+0xe5/0x170 [62852.053645] [] dev_change_flags+0x29/0x60 [62852.053647] [] vlan_device_event+0x18a/0x690 [8021q] [62852.053649] [] notifier_call_chain+0x4c/0x70 [62852.053651] [] raw_notifier_call_chain+0x16/0x20 [62852.053653] [] call_netdevice_notifiers+0x2d/0x60 [62852.053654] [] __dev_notify_flags+0x33/0xa0 [62852.053656] [] dev_change_flags+0x52/0x60 [62852.053657] [] do_setlink+0x397/0xa40 And this one comes from the notification code. What we end up with is a vlan with promiscuity count of 1 and and a physical device with a promiscuity count of 2. They should both have a count 1. To resolve this issue, vlan code can use dev_get_flags() api which correctly masks promiscuity and allmulti flags. Sign-off-by: Vlad Yasevich --- net/8021q/vlan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 98a30a5..59555f0 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -443,7 +443,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, case NETDEV_UP: /* Put all VLANs for this dev in the up state too. */ vlan_group_for_each_dev(grp, i, vlandev) { - flgs = vlandev->flags; + flgs = dev_get_flags(vlandev); if (flgs & IFF_UP) continue; -- 1.9.3