From eb3e554b4b3a56386ef5214dbe0e3935a350178b 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 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 Cc: stable@kernel.org Signed-off-by: John W. Linville --- net/mac80211/tx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 5950e3a..b64b42b 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2230,6 +2230,9 @@ 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) -- 2.7.4