[ 17/50] ath9k: fix key allocation error handling for powersave keys

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felix Fietkau <nbd@openwrt.org>

commit 4ef69d0394cba8caa9f75d3f2e53429bfb8b3045 upstream.

If no keycache slots are available, ath_key_config can return -ENOSPC.
If the key index is not checked for errors, it can lead to logspam that
looks like this: "ath: wiphy0: keyreset: keycache entry 228 out of range"
This can cause follow-up errors if the invalid keycache index gets
used for tx.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/wireless/ath/ath9k/main.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1711,6 +1711,7 @@ static int ath9k_sta_add(struct ieee8021
 	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 = { };
+	int key;
 
 	ath_node_attach(sc, sta, vif);
 
@@ -1718,7 +1719,9 @@ static int ath9k_sta_add(struct ieee8021
 	    vif->type != NL80211_IFTYPE_AP_VLAN)
 		return 0;
 
-	an->ps_key = ath_key_config(common, vif, sta, &ps_key);
+	key = ath_key_config(common, vif, sta, &ps_key);
+	if (key > 0)
+		an->ps_key = key;
 
 	return 0;
 }
@@ -1735,6 +1738,7 @@ static void ath9k_del_ps_key(struct ath_
 	    return;
 
 	ath_key_delete(common, &ps_key);
+	an->ps_key = 0;
 }
 
 static int ath9k_sta_remove(struct ieee80211_hw *hw,