From: Adrian Drzewiecki <z@drze.net>
Date: Wed, 15 Feb 2006 09:47:48 +0000 (-0800)
Subject: [BRIDGE]: Fix deadlock in br_stp_disable_bridge
X-Git-Tag: firefly_0821_release~38003^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=78872ccb68335b14f0d1ac7338ecfcbf1cba1df4;p=firefly-linux-kernel-4.4.55.git

[BRIDGE]: Fix deadlock in br_stp_disable_bridge

Looks like somebody forgot to use the _bh spin_lock variant. We ran into a
deadlock where br->hello_timer expired while br_stp_disable_br() walked
br->port_list.

Signed-off-by: Adrian Drzewiecki <z@drze.net>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index cc047f7fb6ef..35cf3a074087 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -67,7 +67,7 @@ void br_stp_disable_bridge(struct net_bridge *br)
 {
 	struct net_bridge_port *p;
 
-	spin_lock(&br->lock);
+	spin_lock_bh(&br->lock);
 	list_for_each_entry(p, &br->port_list, list) {
 		if (p->state != BR_STATE_DISABLED)
 			br_stp_disable_port(p);
@@ -76,7 +76,7 @@ void br_stp_disable_bridge(struct net_bridge *br)
 
 	br->topology_change = 0;
 	br->topology_change_detected = 0;
-	spin_unlock(&br->lock);
+	spin_unlock_bh(&br->lock);
 
 	del_timer_sync(&br->hello_timer);
 	del_timer_sync(&br->topology_change_timer);