[PATCH 3.16 003/245] libertas: don't exit from lbs_ibss_join_existing() with RCU read lock held

[Ben Hutchings]

3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Nicolai Stange <nstange@xxxxxxx>

commit c7bf1fb7ddca331780b9a733ae308737b39f1ad4 upstream.

Commit e5e884b42639 ("libertas: Fix two buffer overflows at parsing bss
descriptor") introduced a bounds check on the number of supplied rates to
lbs_ibss_join_existing().

Unfortunately, it introduced a return path from within a RCU read side
critical section without a corresponding rcu_read_unlock(). Fix this.

Fixes: e5e884b42639 ("libertas: Fix two buffer overflows at parsing bss descriptor")
Signed-off-by: Nicolai Stange <nstange@xxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/wireless/libertas/cfg.c | 1 +
 1 file changed, 1 insertion(+)

--- a/drivers/net/wireless/libertas/cfg.c
+++ b/drivers/net/wireless/libertas/cfg.c
@@ -1855,6 +1855,7 @@ static int lbs_ibss_join_existing(struct
 		rates_max = rates_eid[1];
 		if (rates_max > MAX_RATES) {
 			lbs_deb_join("invalid rates");
+			rcu_read_unlock();
 			goto out;
 		}
 		rates = cmd.bss.rates;