From 481335e5059076b32e768545d6a5d9bafa5ba84d Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 24 Jan 2011 19:28:49 +0100 Subject: [PATCH] mac80211: fix a crash in ieee80211_beacon_get_tim on change_interface commit eb3e554b4b3a56386ef5214dbe0e3935a350178b upstream. Some drivers (e.g. ath9k) do not always disable beacons when they're supposed to. When an interface is changed using the change_interface op, the mode specific sdata part is in an undefined state and trying to get a beacon at this point can produce weird crashes. To fix this, add a check for ieee80211_sdata_running before using anything from the sdata. Signed-off-by: Felix Fietkau Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- net/mac80211/tx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index ab6355dd4ac0..fad02ea11520 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2175,6 +2175,9 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw, sdata = vif_to_sdata(vif); + if (!ieee80211_sdata_running(sdata)) + goto out; + if (tim_offset) *tim_offset = 0; if (tim_length) -- 2.39.5