mac80211: check management frame header length (4a4f1a58) · Commits · 戴 / test

Due to pskb_may_pull() checking the skb length, all non-management frames are checked on input whether their 802.11 header is fully present. Also add that check for management frames and remove a check that is now duplicate. This prevents accessing skb data beyond the frame end. Cc: stable@vger.kernel.org Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1470,7 +1470,6 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
		frag = sc & IEEE80211_SCTL_FRAG;

		if (likely((!ieee80211_has_morefrags(fc) && frag == 0) \|\|
		(rx->skb)->len < 24 \|\|
		is_multicast_ether_addr(hdr->addr1))) {
		/* not fragmented */
		goto out;
		@@ -2915,10 +2914,15 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
		if (ieee80211_is_data(fc) \|\| ieee80211_is_mgmt(fc))
		local->dot11ReceivedFragmentCount++;

		if (ieee80211_is_mgmt(fc))
		err = skb_linearize(skb);
		if (ieee80211_is_mgmt(fc)) {
		/* drop frame if too short for header */
		if (skb->len < ieee80211_hdrlen(fc))
		err = -ENOBUFS;
		else
		err = skb_linearize(skb);
		} else {
		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
		}

		if (err) {
		dev_kfree_skb(skb);

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