mac80211: check return value of dev_alloc_skb() in ieee80211_sta_join_ibss().

This patch add a check on the return value of dev_alloc_skb() in
ieee80211_sta_join_ibss() in net/mac80211/mlme.c.
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -1379,6 +1379,13 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_supported_band *sband;
 	union iwreq_data wrqu;
 
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
+		       "response\n", sdata->dev->name);
+		return -ENOMEM;
+	}
+
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 
 	/* Remove possible STA entries from other IBSS networks. */
@@ -1404,8 +1411,7 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 		return res;
 
 	/* Build IBSS probe response */
-	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
-	if (skb) {
+
 	skb_reserve(skb, local->hw.extra_tx_headroom);
 
 	mgmt = (struct ieee80211_mgmt *)
@@ -1459,7 +1465,7 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	ifsta->probe_resp = skb;
 
 	ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
-	}
+
 
 	rates = 0;
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];