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

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: c83b8fab06 ("bridge: Restart queries when last querier expires")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nikolay Aleksandrov 2019-04-11 15:08:25 +03:00 committed by David S. Miller
parent 9a4dda81f1
commit c5b493ce19
1 changed files with 3 additions and 1 deletions

View File

@ -2031,7 +2031,8 @@ 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;
@ -2043,6 +2044,7 @@ 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)