Subject: Re: [PATCH net-next] macvlan: Replace strncpy() by strscpy()

From: Stephen Hemminger <[email-masked]>
Date: Mon, 27 May 2019 14:33:41 -0700

On Mon, 27 May 2019 16:28:05 -0500
"Gustavo A. R. Silva" <[email-masked]> wrote:

> On 5/27/19 4:20 PM, Stephen Hemminger wrote:
> > On Mon, 27 May 2019 13:38:55 -0500
> > "Gustavo A. R. Silva" <[email-masked]> wrote:
> >   
> >> The strncpy() function is being deprecated. Replace it by the safer
> >> strscpy() and fix the following Coverity warning:
> >>
> >> "Calling strncpy with a maximum size argument of 16 bytes on destination
> >> array ifrr.ifr_ifrn.ifrn_name of size 16 bytes might leave the destination
> >> string unterminated."
> >>
> >> Notice that, unlike strncpy(), strscpy() always null-terminates the
> >> destination string.
> >>
> >> Addresses-Coverity-ID: 1445537 ("Buffer not null terminated")
> >> Signed-off-by: Gustavo A. R. Silva <[email-masked]>
> >> ---
> >>  drivers/net/macvlan.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> >> index 61550122b563..0ccabde8e9c9 100644
> >> --- a/drivers/net/macvlan.c
> >> +++ b/drivers/net/macvlan.c
> >> @@ -831,7 +831,7 @@ static int macvlan_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> >>  	struct ifreq ifrr;
> >>  	int err = -EOPNOTSUPP;
> >>  
> >> -	strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
> >> +	strscpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
> >>  	ifrr.ifr_ifru = ifr->ifr_ifru;
> >>  
> >>  	switch (cmd) {  
> > 
> > Why not use strlcpy like all the other places IFNAMSIZ is copied?
> >   
> 
> strlcpy() is also being deprecated.

Are you going to fix all these:
$ git grep strlcpy | grep IFNAMSIZ| wc -l
47