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* [PATCHv2 0/2] bonding: NULL pointer dereference and flag strip fixes
@ 2013-04-11 19:18 Nikolay Aleksandrov
  2013-04-11 19:18 ` [PATCHv2 1/2] bonding: fix netdev event NULL pointer dereference Nikolay Aleksandrov
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Nikolay Aleksandrov @ 2013-04-11 19:18 UTC (permalink / raw)
  To: netdev; +Cc: andy, fubar, davem

 These 2 patches fix a NULL pointer dereference in the netdev event
 handling of the bond and flag that wasn't stripped on enslave failure.

v2: Fix comment style 

Nikolay Aleksandrov (2):
  bonding: fix netdev event NULL pointer dereference
  bonding: IFF_BONDING is not stripped on enslave failure

 drivers/net/bonding/bond_main.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

-- 
1.8.1.4

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 1/2] bonding: fix netdev event NULL pointer dereference
@ 2013-04-09 20:17 Nikolay Aleksandrov
  2013-04-11 13:45 ` [PATCHv2 " Nikolay Aleksandrov
  0 siblings, 1 reply; 6+ messages in thread
From: Nikolay Aleksandrov @ 2013-04-09 20:17 UTC (permalink / raw)
  To: netdev; +Cc: andy, fubar, davem

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.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
---
 drivers/net/bonding/bond_main.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 171b10f..9995ddc 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3168,11 +3168,21 @@ 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)
-- 
1.8.1.4

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-04-11 20:02 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2013-04-11 19:18 [PATCHv2 0/2] bonding: NULL pointer dereference and flag strip fixes Nikolay Aleksandrov
2013-04-11 19:18 ` [PATCHv2 1/2] bonding: fix netdev event NULL pointer dereference Nikolay Aleksandrov
2013-04-11 19:18 ` [PATCHv2 2/2] bonding: IFF_BONDING is not stripped on enslave failure Nikolay Aleksandrov
2013-04-11 20:02 ` [PATCHv2 0/2] bonding: NULL pointer dereference and flag strip fixes David Miller
  -- strict thread matches above, loose matches on Subject: below --
2013-04-09 20:17 [PATCH 1/2] bonding: fix netdev event NULL pointer dereference Nikolay Aleksandrov
2013-04-11 13:45 ` [PATCHv2 " Nikolay Aleksandrov
2013-04-11 17:28   ` David Miller

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