diff mbox

[091/115] bridge: fix race with topology change timer

Message ID 1369047116-9378-92-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques May 20, 2013, 10:51 a.m. UTC 
3.5.7.13 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: stephen hemminger <stephen@networkplumber.org>

commit 83401eb4990ff6af55aeed8f49681558544192e6 upstream.

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 <jerry.kang@samsung.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 net/bridge/br_stp_timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

diff --git a/net/bridge/br_stp_timer.c b/net/bridge/br_stp_timer.c
index a6747e6..acc63a4 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);