Commit f7d9821a authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller

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: default avatarStephen Hemminger <shemminger@vyatta.com>
Reviewed-by: default avatarNicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f872b237
...@@ -1822,7 +1822,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) ...@@ -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", "but new slave device does not support netpoll.\n",
bond_dev->name); bond_dev->name);
res = -EBUSY; res = -EBUSY;
goto err_close; goto err_detach;
} }
} }
#endif #endif
...@@ -1831,7 +1831,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) ...@@ -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); res = bond_create_slave_symlinks(bond_dev, slave_dev);
if (res) if (res)
goto err_close; goto err_detach;
res = netdev_rx_handler_register(slave_dev, bond_handle_frame, res = netdev_rx_handler_register(slave_dev, bond_handle_frame,
new_slave); new_slave);
...@@ -1852,6 +1852,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) ...@@ -1852,6 +1852,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
err_dest_symlinks: err_dest_symlinks:
bond_destroy_slave_symlinks(bond_dev, slave_dev); 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: err_close:
dev_close(slave_dev); dev_close(slave_dev);
......
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