Commit 97fd88e0 authored Apr 11, 2019 by Nikolay Aleksandrov Committed by Greg Kroah-Hartman Apr 27, 2019

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: c83b8fab ("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>

parent 08b0b4f2

net/bridge/br_multicast.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -2152,7 +2152,8 @@ 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;
		@@ -2164,6 +2165,7 @@ 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)