mac80211_hwsim: initialize ieee80211_tx_info at hw_scan_work

In mac80211_hwsim, the probe_req frame is created and sent while
scanning. It is sent with ieee80211_tx_info which is not initialized.
Uninitialized ieee80211_tx_info can cause problems when using
mac80211_hwsim with wmediumd. wmediumd checks the tx_rates field of
ieee80211_tx_info and doesn't relay probe_req frame to other clients
even if it is a broadcasting message.

Call ieee80211_tx_prepare_skb() to initialize ieee80211_tx_info for
the probe_req that is created by hw_scan_work in mac80211_hwsim.
Signed-off-by: JaeMan Park <jaeman@google.com>
Link: https://lore.kernel.org/r/20220113060235.546107-1-jaeman@google.com
[fix memory leak]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -2336,6 +2336,15 @@ static void hw_scan_work(struct work_struct *work)
 			if (req->ie_len)
 				skb_put_data(probe, req->ie, req->ie_len);
 
+			if (!ieee80211_tx_prepare_skb(hwsim->hw,
+						      hwsim->hw_scan_vif,
+						      probe,
+						      hwsim->tmp_chan->band,
+						      NULL)) {
+				kfree_skb(probe);
+				continue;
+			}
+
 			local_bh_disable();
 			mac80211_hwsim_tx_frame(hwsim->hw, probe,
 						hwsim->tmp_chan);