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

[Gustavo A. R. Silva]

On 5/27/19 4:20 PM, Stephen Hemminger wrote:
> On Mon, 27 May 2019 13:38:55 -0500
> "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> 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 <gustavo@xxxxxxxxxxxxxx>
>> ---
>>  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.

--
Gustavo