[PATCH 4.7 037/141] mac80211: check skb_linearize() return value

[Greg Kroah-Hartman]

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

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

From: Johannes Berg <johannes.berg@xxxxxxxxx>

commit 0b97a484e52cb423662eb98904aad82dafcc1f10 upstream.

The A-MSDU TX code (within TXQs) didn't always check the return value
of skb_linearize() properly, resulting in potentially passing a frag-
list SKB down to the driver even when it said it can't handle it. Fix
that.

Fixes: 6e0456b545456 ("mac80211: add A-MSDU tx support")
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/mac80211/tx.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1330,8 +1330,12 @@ out:
 	spin_unlock_bh(&txqi->queue.lock);
 
 	if (skb && skb_has_frag_list(skb) &&
-	    !ieee80211_hw_check(&local->hw, TX_FRAG_LIST))
-		skb_linearize(skb);
+	    !ieee80211_hw_check(&local->hw, TX_FRAG_LIST)) {
+		if (skb_linearize(skb)) {
+			ieee80211_free_txskb(&local->hw, skb);
+			return NULL;
+		}
+	}
 
 	return skb;
 }