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authornikolay@redhat.com <nikolay@redhat.com>2013-04-11 09:18:55 +0000
committerDavid S. Miller <davem@davemloft.net>2013-04-11 16:01:47 -0400
commit6101391d4a381cc0c661d8765235b3cad7da09e5 (patch)
tree02a81e2e58e4fda541f1d3c64cee787bdcdf757f /drivers/net
parentd66954a066158781ccf9c13c91d0316970fe57b6 (diff)
downloadlinux-6101391d4a381cc0c661d8765235b3cad7da09e5.tar.gz
bonding: fix netdev event NULL pointer dereference
In commit 471cb5a33dcbd7c529684a2ac7ba4451414ee4a7 ("bonding: remove usage of dev->master") a bug was introduced which causes a NULL pointer dereference. If a bond device is in mode 6 (ALB) and a slave is added it will dereference a NULL pointer in bond_slave_netdev_event(). This is because in bond_enslave we have bond_alb_init_slave() which changes the MAC address of the slave and causes a NETDEV_CHANGEADDR. Then we have in bond_slave_netdev_event(): struct slave *slave = bond_slave_get_rtnl(slave_dev); struct bonding *bond = slave->bond; bond_slave_get_rtnl() dereferences slave_dev->rx_handler_data which at that time is NULL since netdev_rx_handler_register() is called later. This is fixed by checking if slave is NULL before dereferencing it. v2: Comment style changed. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/bonding/bond_main.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 07401a3e256..e074c6b5551 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3168,11 +3168,20 @@ static int bond_slave_netdev_event(unsigned long event,
struct net_device *slave_dev)
{
struct slave *slave = bond_slave_get_rtnl(slave_dev);
- struct bonding *bond = slave->bond;
- struct net_device *bond_dev = slave->bond->dev;
+ struct bonding *bond;
+ struct net_device *bond_dev;
u32 old_speed;
u8 old_duplex;
+ /* A netdev event can be generated while enslaving a device
+ * before netdev_rx_handler_register is called in which case
+ * slave will be NULL
+ */
+ if (!slave)
+ return NOTIFY_DONE;
+ bond_dev = slave->bond->dev;
+ bond = slave->bond;
+
switch (event) {
case NETDEV_UNREGISTER:
if (bond->setup_by_slave)