From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: [PATCH v3 net-next 0/2] bonding: fix locking in bond_ab_arp_probe Date: Mon, 27 Jan 2014 14:33:31 +0100 Message-ID: <1390829613-1842-1-git-send-email-vfalico@redhat.com> Cc: Jay Vosburgh , Andy Gospodarek , Veaceslav Falico To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23495 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751431AbaA0Nhu (ORCPT ); Mon, 27 Jan 2014 08:37:50 -0500 Sender: netdev-owner@vger.kernel.org List-ID: Hi, After the latest patches, on every call of bond_ab_arp_probe() without an active slave I see the following warning: [ 7.912314] RTNL: assertion failed at net/core/dev.c (4494) ... [ 7.922495] [] dump_stack+0x51/0x72 [ 7.923714] [] netdev_master_upper_dev_get+0x6e/0x70 [ 7.924940] [] rtnl_link_fill+0x116/0x260 [ 7.926143] [] ? dump_stack+0x51/0x72 [ 7.927333] [] rtnl_fill_ifinfo+0x95c/0xb90 [ 7.928529] [] ? __kmalloc_reserve+0x3b/0xa0 [ 7.929681] [] ? __alloc_skb+0x9f/0x1e0 [ 7.930827] [] rtmsg_ifinfo+0x84/0x100 [ 7.931960] [] bond_ab_arp_probe+0x1a7/0x370 [bonding] [ 7.933133] [] bond_activebackup_arp_mon+0x1a8/0x2f0 [bonding] ... It happens because in bond_ab_arp_probe() we change the flags of a slave without holding the RTNL lock. To fix this - remove the useless curr_active_lock, RCUify it and lock RTNL while changing the slave's flags. Also, remove bond_ab_arp_probe() from under any locks in bond_ab_arp_mon(). CC: Jay Vosburgh CC: Andy Gospodarek CC: netdev@vger.kernel.org Signed-off-by: Veaceslav Falico --- drivers/net/bonding/bond_main.c | 48 +++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 21 deletions(-)