diff mbox series

[net,v1] net: wireless: Use kfree_sensitive instead of kfree

Message ID 20230717093456.17474-1-machel@vivo.com (mailing list archive)
State Changes Requested
Delegated to: Kalle Valo
Headers show
Series [net,v1] net: wireless: Use kfree_sensitive instead of kfree | expand

Commit Message

Wang Ming July 17, 2023, 9:34 a.m. UTC
key might contain private part of the key, so better use
kfree_sensitive to free it.

Fixes: 7cec84fdfd88 ("staging: wilc1000: split add_key() to avoid line over 80 chars")
Signed-off-by: Wang Ming <machel@vivo.com>
---
 drivers/net/wireless/microchip/wilc1000/cfg80211.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Greg Kroah-Hartman July 17, 2023, 2:35 p.m. UTC | #1
On Mon, Jul 17, 2023 at 05:34:43PM +0800, Wang Ming wrote:
> key might contain private part of the key, so better use
> kfree_sensitive to free it.

"might"?  What determines if it does, or does not, contain the private
part of the key?

Shouldn't this always be known?

> Fixes: 7cec84fdfd88 ("staging: wilc1000: split add_key() to avoid line over 80 chars")
> Signed-off-by: Wang Ming <machel@vivo.com>
> ---
>  drivers/net/wireless/microchip/wilc1000/cfg80211.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> 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);

For most systems, this would have been wiped when kfree() was called due
to allocation being zeroed out, right?

But, if you want to be safe, and you know this was a private key, that's
fine to do as well, but please figure out if this really is, or is not,
a private key.

thanks,

greg k-h
diff mbox series

Patch

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);
 			priv->wilc_igtk[key_index]->key = NULL;
 			kfree(priv->wilc_igtk[key_index]->seq);
 			priv->wilc_igtk[key_index]->seq = NULL;
@@ -665,7 +665,7 @@  static int del_key(struct wiphy *wiphy, struct net_device *netdev, int link_id,
 		}
 	} else {
 		if (priv->wilc_gtk[key_index]) {
-			kfree(priv->wilc_gtk[key_index]->key);
+			kfree_sensitive(priv->wilc_gtk[key_index]->key);
 			priv->wilc_gtk[key_index]->key = NULL;
 			kfree(priv->wilc_gtk[key_index]->seq);
 			priv->wilc_gtk[key_index]->seq = NULL;
@@ -674,7 +674,7 @@  static int del_key(struct wiphy *wiphy, struct net_device *netdev, int link_id,
 			priv->wilc_gtk[key_index] = NULL;
 		}
 		if (priv->wilc_ptk[key_index]) {
-			kfree(priv->wilc_ptk[key_index]->key);
+			kfree_sensitive(priv->wilc_ptk[key_index]->key);
 			priv->wilc_ptk[key_index]->key = NULL;
 			kfree(priv->wilc_ptk[key_index]->seq);
 			priv->wilc_ptk[key_index]->seq = NULL;