4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> [ Upstream commit 7cb3f9214dfa443c1ccc2be637dcc6344cc203f0 ] Satish reported a problem with the perm multicast router ports not getting reenabled after some series of events, in particular if it happens that the multicast snooping has been disabled and the port goes to disabled state then it will be deleted from the router port list, but if it moves into non-disabled state it will not be re-added because the mcast snooping is still disabled, and enabling snooping later does nothing. Here are the steps to reproduce, setup br0 with snooping enabled and eth1 added as a perm router (multicast_router = 2): 1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping 2. $ ip l set eth1 down ^ This step deletes the interface from the router list 3. $ ip l set eth1 up ^ This step does not add it again because mcast snooping is disabled 4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping 5. $ bridge -d -s mdb show <empty> At this point we have mcast enabled and eth1 as a perm router (value = 2) but it is not in the router list which is incorrect. After this change: 1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping 2. $ ip l set eth1 down ^ This step deletes the interface from the router list 3. $ ip l set eth1 up ^ This step does not add it again because mcast snooping is disabled 4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping 5. $ bridge -d -s mdb show router ports on br0: eth1 Note: we can directly do br_multicast_enable_port for all because the querier timer already has checks for the port state and will simply expire if it's in blocking/disabled. See the comment added by commit 9aa66382163e7 ("bridge: multicast: add a comment to br_port_state_selection about blocking state") Fixes: 561f1103a2b7 ("bridge: Add multicast_snooping sysfs toggle") Reported-by: Satish Ashok <sashok@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/bridge/br_multicast.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -951,13 +951,12 @@ static void br_multicast_enable(struct b mod_timer(&query->timer, jiffies); } -void br_multicast_enable_port(struct net_bridge_port *port) +static void __br_multicast_enable_port(struct net_bridge_port *port) { struct net_bridge *br = port->br; - spin_lock(&br->multicast_lock); if (br->multicast_disabled || !netif_running(br->dev)) - goto out; + return; br_multicast_enable(&port->ip4_own_query); #if IS_ENABLED(CONFIG_IPV6) @@ -965,8 +964,14 @@ void br_multicast_enable_port(struct net #endif if (port->multicast_router == 2 && hlist_unhashed(&port->rlist)) br_multicast_add_router(br, port); +} -out: +void br_multicast_enable_port(struct net_bridge_port *port) +{ + struct net_bridge *br = port->br; + + spin_lock(&br->multicast_lock); + __br_multicast_enable_port(port); spin_unlock(&br->multicast_lock); } @@ -1905,8 +1910,9 @@ static void br_multicast_start_querier(s int br_multicast_toggle(struct net_bridge *br, unsigned long val) { - int err = 0; struct net_bridge_mdb_htable *mdb; + struct net_bridge_port *port; + int err = 0; spin_lock_bh(&br->multicast_lock); if (br->multicast_disabled == !val) @@ -1934,10 +1940,9 @@ rollback: goto rollback; } - br_multicast_start_querier(br, &br->ip4_own_query); -#if IS_ENABLED(CONFIG_IPV6) - br_multicast_start_querier(br, &br->ip6_own_query); -#endif + br_multicast_open(br); + list_for_each_entry(port, &br->port_list, list) + __br_multicast_enable_port(port); unlock: spin_unlock_bh(&br->multicast_lock); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html