libertas: don't exit from lbs_ibss_join_existing() with RCU read lock held

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@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wireless/libertas/cfg.c b/drivers/net/wireless/libertas/cfg.c
index ee5c9a3e1122f887b5551b710df611796d8abb04..4533ee96c3d048ff80a8c5385c56b9839668c92f 100644 (file)
--- 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 lbs_private *priv,
                rates_max = rates_eid[1];
                if (rates_max > MAX_RATES) {
                        lbs_deb_join("invalid rates");
+                       rcu_read_unlock();
                        goto out;
                }
                rates = cmd.bss.rates;