nl80211: validate number of probe response CSA counters

BugLink: http://bugs.launchpad.net/bugs/1629386

commit ad5987b4 upstream.

Due to an apparent copy/paste bug, the number of counters for the
beacon configuration were checked twice, instead of checking the
number of probe response counters. Fix this to check the number of
probe response counters before parsing those.

Fixes: 9a774c78 ("cfg80211: Support multiple CSA counters")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

net/wireless/nl80211.c

@@ -6628,7 +6628,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 
 		params.n_counter_offsets_presp = len / sizeof(u16);
 		if (rdev->wiphy.max_num_csa_counters &&
-		    (params.n_counter_offsets_beacon >
+		    (params.n_counter_offsets_presp >
 		     rdev->wiphy.max_num_csa_counters))
 			return -EINVAL;