RE: [PATCH] IB/mlx5: add checking for "vf" from do_setvfinfo()

[Parav Pandit <parav@mellanox.com>]

Hi Dan,

> -----Original Message-----
> From: Dan Carpenter <dan.carpenter@oracle.com>
> Sent: Tuesday, September 24, 2019 4:21 AM
> To: Parav Pandit <parav@mellanox.com>
> Cc: netdev@vger.kernel.org; Leon Romanovsky <leon@kernel.org>; Eli Cohen
> <eli@mellanox.com>; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe
> <jgg@ziepe.ca>; linux-rdma@vger.kernel.org; kernel-janitors@vger.kernel.org
> Subject: Re: [PATCH] IB/mlx5: add checking for "vf" from do_setvfinfo()
> 
> On Thu, Apr 25, 2019 at 06:15:13AM +0000, Parav Pandit wrote:
> >
> >
> > > -----Original Message-----
> > > From: Dan Carpenter <dan.carpenter@oracle.com>
> > > Sent: Wednesday, April 24, 2019 9:08 AM
> > > To: Parav Pandit <parav@mellanox.com>; netdev@vger.kernel.org
> > > Cc: Leon Romanovsky <leon@kernel.org>; Eli Cohen <eli@mellanox.com>;
> > > Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> > > linux-rdma@vger.kernel.org; kernel-janitors@vger.kernel.org
> > > Subject: Re: [PATCH] IB/mlx5: add checking for "vf" from
> > > do_setvfinfo()
> > >
> > > I think I'm just going to ask netdev for an opinion on this.  It
> > > could be that we're just reading the code wrong...
> > >
> > > I'm getting a lot of Smatch warning about buffer underflows.  The
> > > problem is that Smatch marks everything from nla_data() as unknown
> > > and untrusted user data.  In do_setvfinfo() we get the "->vf" values
> > > from nla_data().  It starts as u32, but all the function pointers in
> > > net_device_ops use it as a signed integer.  Most of the functions
> > > return -EINVAL if "vf" is negative but there are at least 48 which
> > > potentially use negative values as an offset into an array.
> > >
> > > To me making "vf" a u32 throughout seems like a good idea but it's
> > > an extensive patch and I'm not really able to test it at all.
> >
> > I will be try to get you patch early next week for core and in mlx5,
> > tested on mlx5 VFs, that possibly you can carry forward?
> 
> Whatever happened with this?
> 
I had internal few patches that Leon and Saeed reviewed, but it needs more rework at core and driver level.
I haven't had chance to finish it.

> regards,
> dan carpenter