bonding: fix error handling if slave is busy (v2)

If slave device already has a receive handler registered, then the
error unwind of bonding device enslave function is broken.

The following will leave a pointer to freed memory in the slave
device list, causing a later kernel panic.
# modprobe dummy
# ip li add dummy0-1 link dummy0 type macvlan
# modprobe bonding
# echo +dummy0 >/sys/class/net/bond0/bonding/slaves

The fix is to detach the slave (which removes it from the list)
in the unwind path.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger 2011-12-31 13:26:46 +00:00 committed by David S. Miller
parent f872b237c1
commit f7d9821a6a

View File

@ -1822,7 +1822,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
"but new slave device does not support netpoll.\n",
bond_dev->name);
res = -EBUSY;
goto err_close;
goto err_detach;
}
}
#endif
@ -1831,7 +1831,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
res = bond_create_slave_symlinks(bond_dev, slave_dev);
if (res)
goto err_close;
goto err_detach;
res = netdev_rx_handler_register(slave_dev, bond_handle_frame,
new_slave);
@ -1852,6 +1852,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
err_dest_symlinks:
bond_destroy_slave_symlinks(bond_dev, slave_dev);
err_detach:
write_lock_bh(&bond->lock);
bond_detach_slave(bond, new_slave);
write_unlock_bh(&bond->lock);
err_close:
dev_close(slave_dev);