• Mahesh Bandewar's avatar
    bonding: Fix bonding crash · 24b27fc4
    Mahesh Bandewar authored
    Following few steps will crash kernel -
    
      (a) Create bonding master
          > modprobe bonding miimon=50
      (b) Create macvlan bridge on eth2
          > ip link add link eth2 dev mvl0 address aa:0:0:0:0:01 \
    	   type macvlan
      (c) Now try adding eth2 into the bond
          > echo +eth2 > /sys/class/net/bond0/bonding/slaves
          <crash>
    
    Bonding does lots of things before checking if the device enslaved is
    busy or not.
    
    In this case when the notifier call-chain sends notifications, the
    bond_netdev_event() assumes that the rx_handler /rx_handler_data is
    registered while the bond_enslave() hasn't progressed far enough to
    register rx_handler for the new slave.
    
    This patch adds a rx_handler check that can be performed right at the
    beginning of the enslave code to avoid getting into this situation.
    Signed-off-by: 's avatarMahesh Bandewar <maheshb@google.com>
    Acked-by: 's avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
    24b27fc4
netdevice.h 134 KB