From f4fc1623f6a059342ffdac8a6f6b0a1039f4571e Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Thu, 2 May 2013 14:23:28 +0000 Subject: [PATCH] bridge: fix race with topology change timer A bridge should only send topology change notice if it is not the root bridge. It is possible for message age timer to elect itself as a new root bridge, and still have a topology change timer running but waiting for bridge lock on other CPU. Solve the race by checking if we are root bridge before continuing. This was the root cause of the cases where br_send_tcn_bpdu would OOPS. Reported-by: JerryKang Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_stp_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bridge/br_stp_timer.c b/net/bridge/br_stp_timer.c index c3530a81a33bf..950663d4d3303 100644 --- a/net/bridge/br_stp_timer.c +++ b/net/bridge/br_stp_timer.c @@ -107,7 +107,7 @@ static void br_tcn_timer_expired(unsigned long arg) br_debug(br, "tcn timer expired\n"); spin_lock(&br->lock); - if (br->dev->flags & IFF_UP) { + if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) { br_transmit_tcn(br); mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time); -- 2.39.5