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

[Pavel Andrianov]

This is a multi-part message in MIME format.
08.06.2016 02:51, James Cameron ÐÐÑÐÑ:
> On Tue, Jun 07, 2016 at 09:39:55AM -0500, Dan Williams wrote:
> > 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?
> I've hardware, with serial console.
>
> Can test any patch, on USB (8388) or SDIO (8686).
Hi!

I've prepare the patch for this issue. Could you test it?

Thank you.

--
Pavel Andrianov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: andrianov@xxxxxxxxx