bridge: Fix potential deadlock on br->multicast_lock
multicast_lock is taken in softirq context, so we should use
spin_lock_bh() in userspace.
call-chain in softirq context:
run_timer_softirq()
br_multicast_query_expired()
call-chain in userspace:
sysfs_write_file()
store_multicast_snooping()
br_multicast_toggle()
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 995cbe0..2eefe27 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1770,7 +1770,7 @@
int err = 0;
struct net_bridge_mdb_htable *mdb;
- spin_lock(&br->multicast_lock);
+ spin_lock_bh(&br->multicast_lock);
if (br->multicast_disabled == !val)
goto unlock;
@@ -1806,7 +1806,7 @@
}
unlock:
- spin_unlock(&br->multicast_lock);
+ spin_unlock_bh(&br->multicast_lock);
return err;
}