-stable review patch. If anyone has any objections, please let us know.
------------------
Patch to 2.6.15 stable kernel to fix race conditions on device
removal. These are reproducible by doing delif while packets are
in flight.
Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
net/bridge/br_if.c | 7 ++-----
net/bridge/br_input.c | 10 ++++++++--
net/bridge/br_stp_bpdu.c | 8 ++++++--
3 files changed, 16 insertions(+), 9 deletions(-)
Index: linux-2.6.15.3/net/bridge/br_if.c
===================================================================
--- linux-2.6.15.3.orig/net/bridge/br_if.c
+++ linux-2.6.15.3/net/bridge/br_if.c
@@ -99,7 +99,6 @@ static void del_nbp(struct net_bridge_po
struct net_bridge *br = p->br;
struct net_device *dev = p->dev;
- dev->br_port = NULL;
dev_set_promiscuity(dev, -1);
spin_lock_bh(&br->lock);
@@ -110,9 +109,7 @@ static void del_nbp(struct net_bridge_po
list_del_rcu(&p->list);
- del_timer_sync(&p->message_age_timer);
- del_timer_sync(&p->forward_delay_timer);
- del_timer_sync(&p->hold_timer);
+ rcu_assign_pointer(dev->br_port, NULL);
call_rcu(&p->rcu, destroy_nbp_rcu);
}
@@ -217,7 +214,6 @@ static struct net_bridge_port *new_nbp(s
p->dev = dev;
p->path_cost = cost;
p->priority = 0x8000 >> BR_PORT_BITS;
- dev->br_port = p;
p->port_no = index;
br_init_port(p);
p->state = BR_STATE_DISABLED;
@@ -360,6 +356,7 @@ int br_add_if(struct net_bridge *br, str
else if ((err = br_sysfs_addif(p)))
del_nbp(p);
else {
+ rcu_assign_pointer(dev->br_port, p);
dev_set_promiscuity(dev, 1);
list_add_rcu(&p->list, &br->port_list);
Index: linux-2.6.15.3/net/bridge/br_input.c
===================================================================
--- linux-2.6.15.3.orig/net/bridge/br_input.c
+++ linux-2.6.15.3/net/bridge/br_input.c
@@ -45,11 +45,17 @@ static void br_pass_frame_up(struct net_
int br_handle_frame_finish(struct sk_buff *skb)
{
const unsigned char *dest = eth_hdr(skb)->h_dest;
- struct net_bridge_port *p = skb->dev->br_port;
- struct net_bridge *br = p->br;
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
+ struct net_bridge *br;
struct net_bridge_fdb_entry *dst;
int passedup = 0;
+ if (unlikely(!p || p->state == BR_STATE_DISABLED)) {
+ kfree_skb(skb);
+ return 0;
+ }
+
+ br = p->br;
/* insert into forwarding database after filtering to avoid spoofing */
br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
Index: linux-2.6.15.3/net/bridge/br_stp_bpdu.c
===================================================================
--- linux-2.6.15.3.orig/net/bridge/br_stp_bpdu.c
+++ linux-2.6.15.3/net/bridge/br_stp_bpdu.c
@@ -136,10 +136,13 @@ static const unsigned char header[6] = {
/* NO locks */
int br_stp_handle_bpdu(struct sk_buff *skb)
{
- struct net_bridge_port *p = skb->dev->br_port;
- struct net_bridge *br = p->br;
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
+ struct net_bridge *br;
unsigned char *buf;
+ if (!p)
+ goto err;
+
/* insert into forwarding database after filtering to avoid spoofing */
br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
@@ -150,6 +153,7 @@ int br_stp_handle_bpdu(struct sk_buff *s
buf = skb_pull(skb, sizeof(header));
+ br = p->br;
spin_lock_bh(&br->lock);
if (p->state == BR_STATE_DISABLED
|| !(br->dev->flags & IFF_UP)
--