| From 000b7287b67555fee39d39fff75229dedde0dcbf Mon Sep 17 00:00:00 2001 |
| From: Nikolay Aleksandrov <nikolay@nvidia.com> |
| Date: Sun, 11 Jul 2021 12:56:29 +0300 |
| Subject: net: bridge: multicast: fix MRD advertisement router port marking race |
| |
| From: Nikolay Aleksandrov <nikolay@nvidia.com> |
| |
| commit 000b7287b67555fee39d39fff75229dedde0dcbf upstream. |
| |
| When an MRD advertisement is received on a bridge port with multicast |
| snooping enabled, we mark it as a router port automatically, that |
| includes adding that port to the router port list. The multicast lock |
| protects that list, but it is not acquired in the MRD advertisement case |
| leading to a race condition, we need to take it to fix the race. |
| |
| Cc: stable@vger.kernel.org |
| Cc: linus.luessing@c0d3.blue |
| Fixes: 4b3087c7e37f ("bridge: Snoop Multicast Router Advertisements") |
| Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.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, 4 insertions(+) |
| |
| --- a/net/bridge/br_multicast.c |
| +++ b/net/bridge/br_multicast.c |
| @@ -3100,7 +3100,9 @@ static int br_ip4_multicast_mrd_rcv(stru |
| igmp_hdr(skb)->type != IGMP_MRDISC_ADV) |
| return -ENOMSG; |
| |
| + spin_lock(&br->multicast_lock); |
| br_multicast_mark_router(br, port); |
| + spin_unlock(&br->multicast_lock); |
| |
| return 0; |
| } |
| @@ -3168,7 +3170,9 @@ static void br_ip6_multicast_mrd_rcv(str |
| if (icmp6_hdr(skb)->icmp6_type != ICMPV6_MRDISC_ADV) |
| return; |
| |
| + spin_lock(&br->multicast_lock); |
| br_multicast_mark_router(br, port); |
| + spin_unlock(&br->multicast_lock); |
| } |
| |
| static int br_multicast_ipv6_rcv(struct net_bridge *br, |
