diff mbox series

[net,2/2] net: bridge: multicast: fix MRD advertisement router port marking race

Message ID 20210711095629.2986949-3-razor@blackwall.org (mailing list archive)
State Accepted
Commit 000b7287b67555fee39d39fff75229dedde0dcbf
Delegated to: Netdev Maintainers
Headers show
Series net: bridge: multicast: fix automatic router port marking races | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers fail 1 blamed authors not CCed: davem@davemloft.net; 2 maintainers not CCed: davem@davemloft.net kuba@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 18 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Nikolay Aleksandrov July 11, 2021, 9:56 a.m. UTC 
From: Nikolay Aleksandrov <nikolay@nvidia.com>

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>
---
 net/bridge/br_multicast.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 3bbbc6d7b7c3..d0434dc8c03b 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -3277,7 +3277,9 @@  static int br_ip4_multicast_mrd_rcv(struct net_bridge *br,
 	    igmp_hdr(skb)->type != IGMP_MRDISC_ADV)
 		return -ENOMSG;
 
+	spin_lock(&br->multicast_lock);
 	br_ip4_multicast_mark_router(br, port);
+	spin_unlock(&br->multicast_lock);
 
 	return 0;
 }
@@ -3345,7 +3347,9 @@  static void br_ip6_multicast_mrd_rcv(struct net_bridge *br,
 	if (icmp6_hdr(skb)->icmp6_type != ICMPV6_MRDISC_ADV)
 		return;
 
+	spin_lock(&br->multicast_lock);
 	br_ip6_multicast_mark_router(br, port);
+	spin_unlock(&br->multicast_lock);
 }
 
 static int br_multicast_ipv6_rcv(struct net_bridge *br,