net: phy: mscc: macsec: do not copy encryption keys

Following 1b16b3fdf675 ("net: phy: mscc: macsec: clear encryption keys when freeing a flow"),
go one step further and instead of calling memzero_explicit on the key
when freeing a flow, simply not copy the key in the first place as it's
only used when a new flow is set up.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/mscc/mscc_macsec.c b/drivers/net/phy/mscc/mscc_macsec.c
index f81b077..018253a 100644 (file)
--- a/drivers/net/phy/mscc/mscc_macsec.c
+++ b/drivers/net/phy/mscc/mscc_macsec.c
@@ -501,8 +501,7 @@ static u32 vsc8584_macsec_flow_context_id(struct macsec_flow *flow)
 }
 
 /* Derive the AES key to get a key for the hash autentication */
-static int vsc8584_macsec_derive_key(const u8 key[MACSEC_MAX_KEY_LEN],
-                                    u16 key_len, u8 hkey[16])
+static int vsc8584_macsec_derive_key(const u8 *key, u16 key_len, u8 hkey[16])
 {
        const u8 input[AES_BLOCK_SIZE] = {0};
        struct crypto_aes_ctx ctx;
@@ -518,7 +517,8 @@ static int vsc8584_macsec_derive_key(const u8 key[MACSEC_MAX_KEY_LEN],
 }
 
 static int vsc8584_macsec_transformation(struct phy_device *phydev,
-                                        struct macsec_flow *flow)
+                                        struct macsec_flow *flow,
+                                        const u8 *key)
 {
        struct vsc8531_private *priv = phydev->priv;
        enum macsec_bank bank = flow->bank;
@@ -527,7 +527,7 @@ static int vsc8584_macsec_transformation(struct phy_device *phydev,
        u8 hkey[16];
        u64 sci;
 
-       ret = vsc8584_macsec_derive_key(flow->key, priv->secy->key_len, hkey);
+       ret = vsc8584_macsec_derive_key(key, priv->secy->key_len, hkey);
        if (ret)
                return ret;
 
@@ -563,7 +563,7 @@ static int vsc8584_macsec_transformation(struct phy_device *phydev,
        for (i = 0; i < priv->secy->key_len / sizeof(u32); i++)
                vsc8584_macsec_phy_write(phydev, bank,
                                         MSCC_MS_XFORM_REC(index, rec++),
-                                        ((u32 *)flow->key)[i]);
+                                        ((u32 *)key)[i]);
 
        /* Set the authentication key */
        for (i = 0; i < 4; i++)
@@ -632,28 +632,14 @@ static void vsc8584_macsec_free_flow(struct vsc8531_private *priv,
 
        list_del(&flow->list);
        clear_bit(flow->index, bitmap);
-       memzero_explicit(flow->key, sizeof(flow->key));
        kfree(flow);
 }
 
-static int vsc8584_macsec_add_flow(struct phy_device *phydev,
-                                  struct macsec_flow *flow, bool update)
+static void vsc8584_macsec_add_flow(struct phy_device *phydev,
+                                   struct macsec_flow *flow)
 {
-       int ret;
-
        flow->port = MSCC_MS_PORT_CONTROLLED;
        vsc8584_macsec_flow(phydev, flow);
-
-       if (update)
-               return 0;
-
-       ret = vsc8584_macsec_transformation(phydev, flow);
-       if (ret) {
-               vsc8584_macsec_free_flow(phydev->priv, flow);
-               return ret;
-       }
-
-       return 0;
 }
 
 static int vsc8584_macsec_default_flows(struct phy_device *phydev)
@@ -706,6 +692,7 @@ static int __vsc8584_macsec_add_rxsa(struct macsec_context *ctx,
 {
        struct phy_device *phydev = ctx->phydev;
        struct vsc8531_private *priv = phydev->priv;
+       int ret;
 
        flow->assoc_num = ctx->sa.assoc_num;
        flow->rx_sa = ctx->sa.rx_sa;
@@ -717,19 +704,39 @@ static int __vsc8584_macsec_add_rxsa(struct macsec_context *ctx,
        if (priv->secy->validate_frames != MACSEC_VALIDATE_DISABLED)
                flow->match.untagged = 1;
 
-       return vsc8584_macsec_add_flow(phydev, flow, update);
+       vsc8584_macsec_add_flow(phydev, flow);
+
+       if (update)
+               return 0;
+
+       ret = vsc8584_macsec_transformation(phydev, flow, ctx->sa.key);
+       if (ret)
+               vsc8584_macsec_free_flow(phydev->priv, flow);
+
+       return ret;
 }
 
 static int __vsc8584_macsec_add_txsa(struct macsec_context *ctx,
                                     struct macsec_flow *flow, bool update)
 {
+       int ret;
+
        flow->assoc_num = ctx->sa.assoc_num;
        flow->tx_sa = ctx->sa.tx_sa;
 
        /* Always match untagged packets on egress */
        flow->match.untagged = 1;
 
-       return vsc8584_macsec_add_flow(ctx->phydev, flow, update);
+       vsc8584_macsec_add_flow(ctx->phydev, flow);
+
+       if (update)
+               return 0;
+
+       ret = vsc8584_macsec_transformation(ctx->phydev, flow, ctx->sa.key);
+       if (ret)
+               vsc8584_macsec_free_flow(ctx->phydev->priv, flow);
+
+       return ret;
 }
 
 static int vsc8584_macsec_dev_open(struct macsec_context *ctx)
@@ -829,8 +836,6 @@ static int vsc8584_macsec_add_rxsa(struct macsec_context *ctx)
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       memcpy(flow->key, ctx->sa.key, priv->secy->key_len);
-
        ret = __vsc8584_macsec_add_rxsa(ctx, flow, false);
        if (ret)
                return ret;
@@ -882,8 +887,6 @@ static int vsc8584_macsec_add_txsa(struct macsec_context *ctx)
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       memcpy(flow->key, ctx->sa.key, priv->secy->key_len);
-
        ret = __vsc8584_macsec_add_txsa(ctx, flow, false);
        if (ret)
                return ret;

diff --git a/drivers/net/phy/mscc/mscc_macsec.h b/drivers/net/phy/mscc/mscc_macsec.h
index 453304b..21ce3b8 100644 (file)
--- a/drivers/net/phy/mscc/mscc_macsec.h
+++ b/drivers/net/phy/mscc/mscc_macsec.h
@@ -81,8 +81,6 @@ struct macsec_flow {
        /* Highest takes precedence [0..15] */
        u8 priority;
 
-       u8 key[MACSEC_MAX_KEY_LEN];
-
        union {
                struct macsec_rx_sa *rx_sa;
                struct macsec_tx_sa *tx_sa;