• Ido Schimmel's avatar
    switchdev: Require RTNL mutex to be held when sending FDB notifications · 4f2c6ae5
    Ido Schimmel authored
    When switchdev drivers process FDB notifications from the underlying
    device they resolve the netdev to which the entry points to and notify
    the bridge using the switchdev notifier.
    
    However, since the RTNL mutex is not held there is nothing preventing
    the netdev from disappearing in the middle, which will cause
    br_switchdev_event() to dereference a non-existing netdev.
    
    Make switchdev drivers hold the lock at the beginning of the
    notification processing session and release it once it ends, after
    notifying the bridge.
    
    Also, remove switchdev_mutex and fdb_lock, as they are no longer needed
    when RTNL mutex is held.
    
    Fixes: 03bf0c28 ("switchdev: introduce switchdev notifier")
    Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
    Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4f2c6ae5
switchdev.c 34.6 KB