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Commit 77a980dc authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

mac80211: fix RX skb leaks 



In mac80211's RX path some of the warnings that
warn about drivers passing invalid status values
leak the skb, fix that by refactoring the code.

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 0448b5fc

net/mac80211/rx.c

+15 −19
Original line number Diff line number Diff line
@@ -2447,17 +2447,13 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb) 
	struct ieee80211_supported_band *sband;

	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);



	if (status->band < 0 ||

	    status->band >= IEEE80211_NUM_BANDS) {

		WARN_ON(1);

		return;

	}

	if (WARN_ON(status->band < 0 ||

		    status->band >= IEEE80211_NUM_BANDS))

		goto drop;



	sband = local->hw.wiphy->bands[status->band];

	if (!sband) {

		WARN_ON(1);

		return;

	}

	if (WARN_ON(!sband))

		goto drop;



	/*

	 * If we're suspending, it is possible although not too likely
@@ -2466,25 +2462,21 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb) 
	 * that might, for example, cause stations to be added or other

	 * driver callbacks be invoked.

	 */

	if (unlikely(local->quiescing || local->suspended)) {

		kfree_skb(skb);

		return;

	}

	if (unlikely(local->quiescing || local->suspended))

		goto drop;



	/*

	 * The same happens when we're not even started,

	 * but that's worth a warning.

	 */

	if (WARN_ON(!local->started)) {

		kfree_skb(skb);

		return;

	}

	if (WARN_ON(!local->started))

		goto drop;



	if (status->flag & RX_FLAG_HT) {

		/* rate_idx is MCS index */

		if (WARN_ON(status->rate_idx < 0 ||

			    status->rate_idx >= 76))

			return;

			goto drop;

		/* HT rates are not in the table - use the highest legacy rate

		 * for now since other parts of mac80211 may not yet be fully

		 * MCS aware. */
@@ -2492,7 +2484,7 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb) 
	} else {

		if (WARN_ON(status->rate_idx < 0 ||

			    status->rate_idx >= sband->n_bitrates))

			return;

			goto drop;

		rate = &sband->bitrates[status->rate_idx];

	}
@@ -2531,6 +2523,10 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb) 
		__ieee80211_rx_handle_packet(hw, skb, rate);



	rcu_read_unlock();



	return;

 drop:

	kfree_skb(skb);

}

EXPORT_SYMBOL(ieee80211_rx);