mwifiex: fix unbalanced locking in mwifiex_process_country_ie()

We called rcu_read_lock(), so we need to call rcu_read_unlock() before
we return.

Fixes: 3d94a4a ("mwifiex: fix possible heap overflow in mwifiex_process_country_ie()")
Cc: [email protected]
Cc: huangwen <[email protected]>
Cc: Ganapathi Bhat <[email protected]>
Signed-off-by: Brian Norris <[email protected]>
Acked-by: Ganapathi Bhat <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
(cherry picked from commit 65b1aae)

Orabug: 30781857
CVE: CVE-2019-14895

Signed-off-by: Vijayendra Suman <[email protected]>
Reviewed-by: Allen Pais <[email protected]>
Signed-off-by: Somasundaram Krishnasamy <[email protected]>

Author: computersforpeace

drivers/net/wireless/marvell/mwifiex/sta_ioctl.c

@@ -274,6 +274,7 @@ static int mwifiex_process_country_ie(struct mwifiex_private *priv,
 
 	if (country_ie_len >
 	    (IEEE80211_COUNTRY_STRING_LEN + MWIFIEX_MAX_TRIPLET_802_11D)) {
+		rcu_read_unlock();
 		mwifiex_dbg(priv->adapter, ERROR,
 			    "11D: country_ie_len overflow!, deauth AP\n");
 		return -EINVAL;