Re: [ldv-project] [net] libertas: potential race condition

On Tue, 2016-06-07 at 13:30 +0400, Pavel Andrianov wrote:

Hi!

There is a potential race condition in 
drivers/net/wireless/libertas/libertas.ko.
In the function lbs_hard_start_xmit(..), line 159, a socket buffer
is 
written to priv->current_skb with a spin_lock protection.
In the function lbs_mac_event_disconnected(..), lines 50-51, the
field 
current_skb is cleaned. There is no protection used. The
corresponding 
handlers are activated at the same time in lbs_start_card(..) and
then 
may be executed simultaneously. Note, there are two structures 
lbs_netdev_ops and mesh_netdev_ops, which have the target handler 
lbs_hard_start_xmit.
Is it a real race or I have missed something?

Yeah, it looks like it should be grabbing priv->driver_lock before
clearing priv->currenttxskb in lbs_mac_event_disconnected().  Care to
submit a patch after testing?  Do you have any of that hardware?

Dan