Re: [PATCH v3] staging: rtl8723bs: stop overreading monitor interface name

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Sep 29, 2026 at 07:18:11PM +0330, Amirhossein Hajimohammadi wrote:
> From: AmirHossein HajiMohammadi <info@hajimohammadi.net>
> 
> cfg80211 passes a NUL-terminated interface name. memcpy() always reads
> IFNAMSIZ + 1 bytes, even when the caller supplied a shorter string.
> 
> Use strscpy() to stop at the terminator and bound the write to the
> destination buffer.
> 
> Signed-off-by: AmirHossein HajiMohammadi <info@hajimohammadi.net>
> ---
> Changes in v3:
> - Add an explicit From header matching the Signed-off-by identity.
> 
> Changes in v2:
> - Send the patch inline instead of as a MIME attachment.
> 
>  drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> index 4416d0ec1..8f5032844 100644
> --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> @@ -2158,7 +2158,7 @@ static int rtw_cfg80211_add_monitor_if(struct adapter *padapter, char *name, str
>  		goto out;
>  
>  	*ndev = pwdev_priv->pmon_ndev = mon_ndev;
> -	memcpy(pwdev_priv->ifname_mon, name, IFNAMSIZ + 1);
> +	strscpy(pwdev_priv->ifname_mon, name);

But we are replacing str*() calls in the kernel with memcpy() calls
where it can happen, so why go backwards here?

What caused you to notice this change is needed?  Have you measured a
speed up in throughput with this change applied?  How was it tested?

thanks,

greg k-h