From: Felix Fietkau Date: Mon, 24 Jan 2011 18:28:49 +0000 (+0100) Subject: mac80211: fix a crash in ieee80211_beacon_get_tim on change_interface X-Git-Tag: v2.6.37.1~220 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=04e0f5f7ed4fe711325d4d62b80f1f2031db9614;p=karo-tx-linux.git 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 --- diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 7a637b80a62e..e2d33cf0c407 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2207,6 +2207,9 @@ 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)