mac80211_hwsim: avoid NULL access

There's a race condition -- started can be set to true
before channel is set due to the way mac80211 callbacks
currently work (->start should probably pass the channel
we would like to have initially). For now simply add a
check to hwsim to avoid dereferencing the NULL channel
pointer.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index e789c6e9938..a111bda392e 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -418,6 +418,7 @@ static bool mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
                         continue;
 
                 if (!data2->started || !hwsim_ps_rx_ok(data2, skb) ||
+                    !data->channel || !data2->channel ||
                     data->channel->center_freq != data2->channel->center_freq ||
                     !(data->group & data2->group))
                         continue;