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Date:   Thu, 29 Dec 2022 12:54:28 +0300
From:   Dan Carpenter <error27@gmail.com>
To:     yang.yang29@zte.com.cn
Cc:     gustavoars@kernel.org, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org, xu.panda@zte.com.cn
Subject: Re: [PATCH linux-next] staging: ks7010: use strscpy() to instead of
 strncpy()
Message-ID: <Y61j1JRx0ZMeVjji@kadam>
References: <202212261903245548969@zte.com.cn>
 <Y61hpuMcp3NKbqL5@kadam>
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On Thu, Dec 29, 2022 at 12:45:10PM +0300, Dan Carpenter wrote:
> On Mon, Dec 26, 2022 at 07:03:24PM +0800, yang.yang29@zte.com.cn wrote:
> > From: Xu Panda <xu.panda@zte.com.cn>
> > 
> > The implementation of strscpy() is more robust and safer.
> > That's now the recommended way to copy NUL-terminated strings.
> > 
> > Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
> > Signed-off-by: Yang Yang <yang.yang29@zte.com>
> > ---
> >  drivers/staging/ks7010/ks_wlan_net.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/drivers/staging/ks7010/ks_wlan_net.c b/drivers/staging/ks7010/ks_wlan_net.c
> > index 044c807ca022..e03c87f0bfe7 100644
> > --- a/drivers/staging/ks7010/ks_wlan_net.c
> > +++ b/drivers/staging/ks7010/ks_wlan_net.c
> > @@ -382,8 +382,7 @@ static int ks_wlan_get_nick(struct net_device *dev,
> >  		return -EPERM;
> > 
> >  	/* for SLEEP MODE */
> > -	strncpy(extra, priv->nick, 16);
> > -	extra[16] = '\0';
> > +	strscpy(extra, priv->nick, 17);
> 
> I think this code is a buffer overflow.  This is an implementation of
> SIOCGIWNICKN.
> 
> net/wireless/wext-core.c
>    169          [IW_IOCTL_IDX(SIOCGIWNICKN)] = {
>    170                  .header_type    = IW_HEADER_TYPE_POINT,
>    171                  .token_size     = 1,
>    172                  .max_tokens     = IW_ESSID_MAX_SIZE,
>    173          },
> 

Yeah.  I was wrong.  The extra size here is .max_tokens * .token_size so
it's 32.

Sorry for the noise!

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter