From: Nikolay Aleksandrov nikolay@cumulusnetworks.com
[ 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 --- net/bridge/br_multicast.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1916,7 +1916,8 @@ static void br_multicast_start_querier(s
__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; @@ -1928,6 +1929,7 @@ static void br_multicast_start_querier(s br_multicast_enable(&port->ip6_own_query); #endif } + rcu_read_unlock(); }
int br_multicast_toggle(struct net_bridge *br, unsigned long val)