From 6dbda2d00d466225f9db1dc695ff852443f28832 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 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. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- 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 265a032dec49..00ade7feb2e3 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -888,14 +888,16 @@ 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, ðertype, 2); + if (ethertype == rx->sdata->control_port_protocol) return RX_CONTINUE; } -- 2.20.1