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 <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Felix Fietkau 2011-01-24 19:28:49 +01:00 committed by Greg Kroah-Hartman
parent 4408bef5c1
commit 04e0f5f7ed

View File

@ -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)