Re: [RESEND PATCH-next] staging: rtl8723bs: replace deprecated strncpy with strscpy_pad

From: Dan Carpenter
Date: Wed Dec 13 2023 - 08:13:46 EST


On Wed, Dec 13, 2023 at 09:18:40AM +0800, xueqin Luo wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We should NUL-pad as there are full struct copies happening in places:
> | case NL80211_IFTYPE_MONITOR:
> | ret = rtw_cfg80211_add_monitor_if(padapter,
> | (char *)name, &ndev);
> | break;
>

I don't see where the full copy is... What you're looking for is some
place that copies "mon_ndev->name" to the user.

> A suitable replacement is `strscpy_pad` due to the fact that it
> guarantees both NUL-termination and NUL-padding on the destination
> buffer.
>
> Additionally, replace size macro `IFNAMSIZ` with sizeof():
> | struct net_device {
> | char name[IFNAMSIZ];
> | ...

This would normally be the right move but IFNAMSIZ is a really standard
macro that everyone knows.

When I'm reviewing this code, I later on see a line:

memcpy(pwdev_priv->ifname_mon, name, IFNAMSIZ + 1);

That means name must be "IFNAMSIZ + 1" characters long or it is a bug.
Please find out where name is set. We need to know how long it is
before we can go any further.

regards,
dan carpenter