From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: [PATCH v2] bonding: fix race condition in bonding_store_slaves_active Date: Thu, 29 Nov 2012 12:37:59 +0100 Message-ID: <1354189079-15754-1-git-send-email-nikolay@redhat.com> References: <1353759595-30452-1-git-send-email-nikolay@redhat.com> Cc: fubar@us.ibm.com, andy@greyhouse.net, davem@davemloft.net To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12993 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751692Ab2K2MSC (ORCPT ); Thu, 29 Nov 2012 07:18:02 -0500 In-Reply-To: <1353759595-30452-1-git-send-email-nikolay@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Race between bonding_store_slaves_active() and slave manipulation functions. The bond_for_each_slave use in bonding_store_slaves_active() is not protected by any synchronization mechanism. NULL pointer dereference is easy to reach. Fixed by acquiring the bond->lock for the slave walk. v2: Make description text < 75 columns Signed-off-by: Nikolay Aleksandrov --- drivers/net/bonding/bond_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index ef8d2a0..ba4f95b 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -1582,6 +1582,7 @@ static ssize_t bonding_store_slaves_active(struct device *d, goto out; } + read_lock(&bond->lock); bond_for_each_slave(bond, slave, i) { if (!bond_is_active_slave(slave)) { if (new_value) @@ -1590,6 +1591,7 @@ static ssize_t bonding_store_slaves_active(struct device *d, slave->inactive = 1; } } + read_unlock(&bond->lock); out: return ret; } -- 1.7.11.7