On Thu, Jul 20, 2023 at 11:06:36AM +0200, Pavel Machek wrote:
> Hi!
>
> > > diff --git a/drivers/net/wireless/microchip/wilc1000/cfg80211.c b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
> > > index b545d93c6e37..45bcadeba2da 100644
> > > --- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c
> > > +++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
> > > @@ -518,7 +518,7 @@ static int wilc_wfi_cfg_allocate_wpa_igtk_entry(struct wilc_priv *priv, u8 idx)
> > > static int wilc_wfi_cfg_copy_wpa_info(struct wilc_wfi_key *key_info,
> > > struct key_params *params)
> > > {
> > > - kfree(key_info->key);
> > > + kfree_sensitive(key_info->key);
> > >
> > > key_info->key = kmemdup(params->key, params->key_len, GFP_KERNEL);
> > > if (!key_info->key)
> > > @@ -656,7 +656,7 @@ static int del_key(struct wiphy *wiphy, struct net_device *netdev, int link_id,
> > > if (!pairwise && (key_index == 4 || key_index == 5)) {
> > > key_index -= 4;
> > > if (priv->wilc_igtk[key_index]) {
> > > - kfree(priv->wilc_igtk[key_index]->key);
> > > + kfree_sensitive(priv->wilc_igtk[key_index]->key);
> >
> > Normally "kfree_sensitive()" is used at the end of a function for when
> > kfree() of a local variable might not be called because the compiler
> > thinks it is smarter than us and optimizes it away.
> >
> > Putting it here, in the normal operation, really doesn't do anything,
> > right? There's always going to be odd data in the heap and normal
>
> It does memzero.
>
> https://elixir.bootlin.com/linux/latest/source/mm/slab_common.c#L1411
I know what it does, I'm saying "why is this required".
