From 0884603402e58608f62f17306aedb33b862d7b6d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 26 Oct 2012 00:41:23 +0200 Subject: [PATCH] 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 Signed-off-by: Ben Hutchings --- net/mac80211/rx.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 348cfa8aacc6..cd6cbdbf2281 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -859,14 +859,16 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx) (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) { if (rx->sta && rx->sta->dummy && 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, ðertype, 2); + if (ethertype == rx->sdata->control_port_protocol) return RX_CONTINUE; } return RX_DROP_MONITOR; -- 2.47.3