| From foo@baz Tue 23 Apr 2019 05:35:42 PM CEST |
| From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> |
| Date: Thu, 11 Apr 2019 15:08:25 +0300 |
| Subject: net: bridge: multicast: use rcu to access port list from br_multicast_start_querier |
| |
| 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 |
| @@ -1983,7 +1983,8 @@ 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; |
| @@ -1995,6 +1996,7 @@ 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) |
