net: bridge: multicast: use rcu to access port list from br_multicast_start_querier

[ Upstream commit c5b493ce192bd7a4e7bd073b5685aad121eeef82 ]

br_multicast_start_querier() walks over the port list but it can be
called from a timer with only multicast_lock held which doesn't protect
the port list, so use RCU to walk over it.

Fixes: c83b8fab06fc ("bridge: Restart queries when last querier expires")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nikolay Aleksandrov 2019-04-11 15:08:25 +03:00 committed by prashantpaddune
parent 3c51d7f957
commit a20e4f0796

View File

@ -1894,7 +1894,8 @@ static void br_multicast_start_querier(struct net_bridge *br,
__br_multicast_open(br, query);
list_for_each_entry(port, &br->port_list, list) {
rcu_read_lock();
list_for_each_entry_rcu(port, &br->port_list, list) {
if (port->state == BR_STATE_DISABLED ||
port->state == BR_STATE_BLOCKING)
continue;
@ -1906,6 +1907,7 @@ static void br_multicast_start_querier(struct net_bridge *br,
br_multicast_enable(&port->ip6_own_query);
#endif
}
rcu_read_unlock();
}
int br_multicast_toggle(struct net_bridge *br, unsigned long val)