From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Nikolay Aleksandrov , Jay Vosburgh , "David S. Miller" Subject: [ 02/47] bonding: fix race condition in bonding_store_slaves_active Date: Wed, 9 Jan 2013 12:34:57 -0800 Message-Id: <20130109201729.739090097@linuxfoundation.org> In-Reply-To: <20130109201729.435233560@linuxfoundation.org> References: <20130109201729.435233560@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "nikolay@redhat.com" [ Upstream commit e196c0e579902f42cf72414461fb034e5a1ffbf7 ] 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 Signed-off-by: Jay Vosburgh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/bonding/bond_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -1524,6 +1524,7 @@ static ssize_t bonding_store_slaves_acti goto out; } + read_lock(&bond->lock); bond_for_each_slave(bond, slave, i) { if (!bond_is_active_slave(slave)) { if (new_value) @@ -1532,6 +1533,7 @@ static ssize_t bonding_store_slaves_acti slave->inactive = 1; } } + read_unlock(&bond->lock); out: return ret; }