Eric Lee / smarc-ti-linux-kernel

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Commit 20a599bec95a52fa72432b2376a2ce47c5bb68fb

Authored by Linus Lüssing
Committed by David S. Miller
1 parent 9ed973cc40
Exists in master and in 16 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

bridge: multicast: enable snooping on general queries only 

Without this check someone could easily create a denial of service
by injecting multicast-specific queries to enable the bridge
snooping part if no real querier issuing periodic general queries
is present on the link which would result in the bridge wrongly
shutting down ports for multicast traffic as the bridge did not learn
about these listeners.

With this patch the snooping code is enabled upon receiving valid,
general queries only.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 5 additions and 3 deletions Side-by-side Diff

net/bridge/br_multicast.c
Diff comments   View file @ 20a599b
... ... @@ -1127,9 +1127,10 @@
1127 1127 struct net_bridge_port *port,
1128 1128 struct bridge_mcast_querier *querier,
1129 1129 int saddr,
  1130 + bool is_general_query,
1130 1131 unsigned long max_delay)
1131 1132 {
1132   - if (saddr)
  1133 + if (saddr && is_general_query)
1133 1134 br_multicast_update_querier_timer(br, querier, max_delay);
1134 1135 else if (timer_pending(&querier->timer))
1135 1136 return;
... ... @@ -1190,7 +1191,7 @@
1190 1191 }
1191 1192  
1192 1193 br_multicast_query_received(br, port, &br->ip4_querier, !!iph->saddr,
1193   - max_delay);
  1194 + !group, max_delay);
1194 1195  
1195 1196 if (!group)
1196 1197 goto out;
... ... @@ -1282,7 +1283,8 @@
1282 1283 }
1283 1284  
1284 1285 br_multicast_query_received(br, port, &br->ip6_querier,
1285   - !ipv6_addr_any(&ip6h->saddr), max_delay);
  1286 + !ipv6_addr_any(&ip6h->saddr),
  1287 + is_general_query, max_delay);
1286 1288  
1287 1289 if (!group)
1288 1290 goto out;