[PATCH net-next v2 8/8] net: core: Convert dev_set_mac_address_user() to use struct sockaddr_storage

[Kees Cook]

On Tue, May 27, 2025 at 09:02:28AM +0200, Paolo Abeni wrote:
> On 5/21/25 10:46 PM, Kees Cook wrote:
> > diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
> > index fff13a8b48f1..616479e71466 100644
> > --- a/net/core/dev_ioctl.c
> > +++ b/net/core/dev_ioctl.c
> > @@ -572,9 +572,11 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
> >  		return dev_set_mtu(dev, ifr->ifr_mtu);
> >  
> >  	case SIOCSIFHWADDR:
> > -		if (dev->addr_len > sizeof(struct sockaddr))
> > +		if (dev->addr_len > sizeof(ifr->ifr_hwaddr))
> >  			return -EINVAL;
> > -		return dev_set_mac_address_user(dev, &ifr->ifr_hwaddr, NULL);
> > +		return dev_set_mac_address_user(dev,
> > +						(struct sockaddr_storage *)&ifr->ifr_hwaddr,
> > +						NULL);
> 
> Side note for a possible follow-up: the above pattern is repeated a
> couple of times: IMHO consolidating it into an helper would be nice.

Yeah, I will look at that.

> Also such helper could/should explicitly convert ifr->ifr_hwaddr to
> sockaddr_storage and avoid the cast.

It's UAPI, so it looked verrrry painful to change.

-- 
Kees Cook