Re: [PATCH v2] net: thunderx: nicvf_main: Fix potential NULL pointer dereferences

[Gustavo A. R. Silva]

On 04/04/2018 01:36 AM, Eric Dumazet wrote:
> On 04/03/2018 03:04 PM, Gustavo A. R. Silva wrote:
> > Add null check on kmalloc() return value in order to prevent
> > a null pointer dereference.
> >
> > Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> > Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> > Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
> > ---
> > Changes in v2:
> >   - Add a null check on a second kmalloc a few lines below. Thanks to
> >     Eric Dumazet for pointing this out.
> >
> >   drivers/net/ethernet/cavium/thunder/nicvf_main.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > index 1e9a31f..f7b5ca5 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > @@ -1999,10 +1999,14 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> >   				struct xcast_addr *xaddr;
> >   
> >   				mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> > +				if (unlikely(!mc_list))
> > +					return;
> >   				INIT_LIST_HEAD(&mc_list->list);
> >   				netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> >   					xaddr = kmalloc(sizeof(*xaddr),
> >   							GFP_ATOMIC);
> > +					if (unlikely(!xaddr))
> > +						return;
>
> So now you leak memory :/

Oh god. I'm sorry.

I had problems with this file since the beginning.

I'll send v3 shortly.

Thanks
--
Gustavo