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@xxxxxxxxxxx> Cc: stable@xxxxxxxxxx --- net/mac80211/tx.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index e46c801..ffc6749 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) -- 1.7.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html