From: Nikolay Aleksandrov nikolay@nvidia.com

commit 04bef83a3358946bfc98a5ecebd1b0003d83d882 upstream.

When a PIM hello packet is received on a bridge port with multicast snooping enabled, we mark it as a router port automatically, that includes adding that port the router port list. The multicast lock protects that list, but it is not acquired in the PIM message case leading to a race condition, we need to take it to fix the race.

Cc: stable@vger.kernel.org Fixes: 91b02d3d133b ("bridge: mcast: add router port on PIM hello message") Signed-off-by: Nikolay Aleksandrov nikolay@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net --- net/bridge/br_multicast.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 6a362da211e1..3504c3acd38f 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1791,7 +1791,9 @@ static void br_multicast_pim(struct net_bridge *br, pim_hdr_type(pimhdr) != PIM_TYPE_HELLO) return;

+ spin_lock(&br->multicast_lock); br_multicast_mark_router(br, port); + spin_unlock(&br->multicast_lock); }

static int br_multicast_ipv4_rcv(struct net_bridge *br,