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authorNikolay Aleksandrov <razor@blackwall.org>2015-06-09 10:23:57 -0700
committerZefan Li <lizefan@huawei.com>2015-09-18 09:20:45 +0800
commit501e81d5d6b9434037851749c6194bf3a237b281 (patch)
tree9c622a22b2974be516a02db2a05ce4237d6e53b9
parent4845c5376dbbf46853b53d5241fbe4d4a2c94b59 (diff)
bridge: fix multicast router rlist endless loop
commit 1a040eaca1a22f8da8285ceda6b5e4a2cb704867 upstream. Since the addition of sysfs multicast router support if one set multicast_router to "2" more than once, then the port would be added to the hlist every time and could end up linking to itself and thus causing an endless loop for rlist walkers. So to reproduce just do: echo 2 > multicast_router; echo 2 > multicast_router; in a bridge port and let some igmp traffic flow, for me it hangs up in br_multicast_flood(). Fix this by adding a check in br_multicast_add_router() if the port is already linked. The reason this didn't happen before the addition of multicast_router sysfs entries is because there's a !hlist_unhashed check that prevents it. Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Fixes: 0909e11758bd ("bridge: Add multicast_router sysfs entries") Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li <lizefan@huawei.com>
-rw-r--r--net/bridge/br_multicast.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index ea1205979ed6..a41051a1bca5 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -991,6 +991,9 @@ static void br_multicast_add_router(struct net_bridge *br,
struct net_bridge_port *p;
struct hlist_node *n, *slot = NULL;
+ if (!hlist_unhashed(&port->rlist))
+ return;
+
hlist_for_each_entry(p, n, &br->router_list, rlist) {
if ((unsigned long) port >= (unsigned long) p)
break;
@@ -1018,12 +1021,8 @@ static void br_multicast_mark_router(struct net_bridge *br,
if (port->multicast_router != 1)
return;
- if (!hlist_unhashed(&port->rlist))
- goto timer;
-
br_multicast_add_router(br, port);
-timer:
mod_timer(&port->multicast_router_timer,
now + br->multicast_querier_interval);
}