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authorJohannes Berg <johannes.berg@intel.com>2012-10-26 00:41:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-17 13:18:31 -0800
commit3a817522b33cb42171cd36f5fa77fa40f447f351 (patch)
treef7647babbf4bc0badf77ce40a2d761260ab11a0a
parent1db96611d45adcc0db12e8f16f78337757cc932e (diff)
mac80211: make sure data is accessible in EAPOL check
commit 6dbda2d00d466225f9db1dc695ff852443f28832 upstream. The code to allow EAPOL frames even when the station isn't yet marked associated needs to check that the incoming frame is long enough and due to paged RX it also can't assume skb->data contains the right data, it must use skb_copy_bits(). Fix this to avoid using data that doesn't really exist. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/mac80211/rx.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6bd9ff8a8349..37fe5cec58e6 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -848,14 +848,16 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
*/
if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
ieee80211_is_data_present(hdr->frame_control)) {
- u16 ethertype;
- u8 *payload;
-
- payload = rx->skb->data +
- ieee80211_hdrlen(hdr->frame_control);
- ethertype = (payload[6] << 8) | payload[7];
- if (cpu_to_be16(ethertype) ==
- rx->sdata->control_port_protocol)
+ unsigned int hdrlen;
+ __be16 ethertype;
+
+ hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+ if (rx->skb->len < hdrlen + 8)
+ return RX_DROP_MONITOR;
+
+ skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
+ if (ethertype == rx->sdata->control_port_protocol)
return RX_CONTINUE;
}