ath: Modify ath_key_delete() to not need full key entry

tkip_keymap can be used internally to avoid the reference to key->cipher
and with this, only the key index value itself is needed. This allows
ath_key_delete() call to be postponed to be handled after the upper
layer STA and key entry have already been removed. This is needed to
make ath9k key cache management safer.

Signed-off-by: Jouni Malinen <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Jouni Malinen

drivers/net/wireless/ath/ath.h

@@ -197,7 +197,7 @@ struct sk_buff *ath_rxbuf_alloc(struct ath_common *common,
 bool ath_is_mybeacon(struct ath_common *common, struct ieee80211_hdr *hdr);
 
 void ath_hw_setbssidmask(struct ath_common *common);
-void ath_key_delete(struct ath_common *common, struct ieee80211_key_conf *key);
+void ath_key_delete(struct ath_common *common, u8 hw_key_idx);
 int ath_key_config(struct ath_common *common,
 			  struct ieee80211_vif *vif,
 			  struct ieee80211_sta *sta,

drivers/net/wireless/ath/ath5k/mac80211-ops.c

@@ -522,7 +522,7 @@ ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		}
 		break;
 	case DISABLE_KEY:
-		ath_key_delete(common, key);
+		ath_key_delete(common, key->hw_key_idx);
 		break;
 	default:
 		ret = -EINVAL;

drivers/net/wireless/ath/ath9k/htc_drv_main.c

@@ -1461,7 +1461,7 @@ static int ath9k_htc_set_key(struct ieee80211_hw *hw,
 		}
 		break;
 	case DISABLE_KEY:
-		ath_key_delete(common, key);
+		ath_key_delete(common, key->hw_key_idx);
 		break;
 	default:
 		ret = -EINVAL;

drivers/net/wireless/ath/ath9k/main.c

@@ -1543,12 +1543,11 @@ static void ath9k_del_ps_key(struct ath_softc *sc,
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 	struct ath_node *an = (struct ath_node *) sta->drv_priv;
-	struct ieee80211_key_conf ps_key = { .hw_key_idx = an->ps_key };
 
 	if (!an->ps_key)
 	    return;
 
-	ath_key_delete(common, &ps_key);
+	ath_key_delete(common, an->ps_key);
 	an->ps_key = 0;
 	an->key_idx[0] = 0;
 }
@@ -1748,7 +1747,7 @@ static int ath9k_set_key(struct ieee80211_hw *hw,
 		}
 		break;
 	case DISABLE_KEY:
-		ath_key_delete(common, key);
+		ath_key_delete(common, key->hw_key_idx);
 		if (an) {
 			for (i = 0; i < ARRAY_SIZE(an->key_idx); i++) {
 				if (an->key_idx[i] != key->hw_key_idx)

drivers/net/wireless/ath/key.c

@@ -581,38 +581,38 @@ EXPORT_SYMBOL(ath_key_config);
 /*
  * Delete Key.
  */
-void ath_key_delete(struct ath_common *common, struct ieee80211_key_conf *key)
+void ath_key_delete(struct ath_common *common, u8 hw_key_idx)
 {
 	/* Leave CCMP and TKIP (main key) configured to avoid disabling
 	 * encryption for potentially pending frames already in a TXQ with the
 	 * keyix pointing to this key entry. Instead, only clear the MAC address
 	 * to prevent RX processing from using this key cache entry.
 	 */
-	if (test_bit(key->hw_key_idx, common->ccmp_keymap) ||
-	    test_bit(key->hw_key_idx, common->tkip_keymap))
-		ath_hw_keysetmac(common, key->hw_key_idx, NULL);
+	if (test_bit(hw_key_idx, common->ccmp_keymap) ||
+	    test_bit(hw_key_idx, common->tkip_keymap))
+		ath_hw_keysetmac(common, hw_key_idx, NULL);
 	else
-		ath_hw_keyreset(common, key->hw_key_idx);
-	if (key->hw_key_idx < IEEE80211_WEP_NKID)
+		ath_hw_keyreset(common, hw_key_idx);
+	if (hw_key_idx < IEEE80211_WEP_NKID)
 		return;
 
-	clear_bit(key->hw_key_idx, common->keymap);
-	clear_bit(key->hw_key_idx, common->ccmp_keymap);
-	if (key->cipher != WLAN_CIPHER_SUITE_TKIP)
+	clear_bit(hw_key_idx, common->keymap);
+	clear_bit(hw_key_idx, common->ccmp_keymap);
+	if (!test_bit(hw_key_idx, common->tkip_keymap))
 		return;
 
-	clear_bit(key->hw_key_idx + 64, common->keymap);
+	clear_bit(hw_key_idx + 64, common->keymap);
 
-	clear_bit(key->hw_key_idx, common->tkip_keymap);
-	clear_bit(key->hw_key_idx + 64, common->tkip_keymap);
+	clear_bit(hw_key_idx, common->tkip_keymap);
+	clear_bit(hw_key_idx + 64, common->tkip_keymap);
 
 	if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
-		ath_hw_keyreset(common, key->hw_key_idx + 32);
-		clear_bit(key->hw_key_idx + 32, common->keymap);
-		clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
+		ath_hw_keyreset(common, hw_key_idx + 32);
+		clear_bit(hw_key_idx + 32, common->keymap);
+		clear_bit(hw_key_idx + 64 + 32, common->keymap);
 
-		clear_bit(key->hw_key_idx + 32, common->tkip_keymap);
-		clear_bit(key->hw_key_idx + 64 + 32, common->tkip_keymap);
+		clear_bit(hw_key_idx + 32, common->tkip_keymap);
+		clear_bit(hw_key_idx + 64 + 32, common->tkip_keymap);
 	}
 }
 EXPORT_SYMBOL(ath_key_delete);