From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: [PATCH v4 net-next 1/3] bonding: fix bond_3ad_set_carrier() RCU usage Date: Fri, 10 Jan 2014 11:59:43 +0100 Message-ID: <1389351585-19615-2-git-send-email-vfalico@redhat.com> References: <1389351585-19615-1-git-send-email-vfalico@redhat.com> Cc: Veaceslav Falico , dingtianhong@huawei.com, Jay Vosburgh , Andy Gospodarek To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:54633 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756670AbaAJLEC (ORCPT ); Fri, 10 Jan 2014 06:04:02 -0500 In-Reply-To: <1389351585-19615-1-git-send-email-vfalico@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Currently, its usage is just plainly wrong. It first gets a slave under RCU, and, after releasing the RCU lock, continues to use it - whilst it can be freed. Fix this by ensuring that bond_3ad_set_carrier() holds RCU till it uses its slave (or its agg). Fixes: be79bd048ab ("bonding: add RCU for bond_3ad_state_machine_handler()") CC: dingtianhong@huawei.com CC: Jay Vosburgh CC: Andy Gospodarek Signed-off-by: Veaceslav Falico --- Notes: v3 -> v4: Remove the useless goto out. v2 -> v3: Just wrap RCU for the whole usage of our slave. v1 -> v2: Don't use _rcu primitives as we can be called under RTNL too. v2 -> v3: Just wrap RCU for the whole usage of our slave. v1 -> v2: Don't use _rcu primitives as we can be called under RTNL too. v1 -> v2: Don't use _rcu primitives as we can be called under RTNL too. drivers/net/bonding/bond_3ad.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index 29db1ca..da0d7c5 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -2327,32 +2327,32 @@ int bond_3ad_set_carrier(struct bonding *bond) { struct aggregator *active; struct slave *first_slave; + int ret = 1; rcu_read_lock(); first_slave = bond_first_slave_rcu(bond); - rcu_read_unlock(); - if (!first_slave) - return 0; + if (!first_slave) { + ret = 0; + goto out; + } active = __get_active_agg(&(SLAVE_AD_INFO(first_slave).aggregator)); if (active) { /* are enough slaves available to consider link up? */ if (active->num_of_ports < bond->params.min_links) { if (netif_carrier_ok(bond->dev)) { netif_carrier_off(bond->dev); - return 1; + goto out; } } else if (!netif_carrier_ok(bond->dev)) { netif_carrier_on(bond->dev); - return 1; + goto out; } - return 0; - } - - if (netif_carrier_ok(bond->dev)) { + } else if (netif_carrier_ok(bond->dev)) { netif_carrier_off(bond->dev); - return 1; } - return 0; +out: + rcu_read_unlock(); + return ret; } /** -- 1.8.4