[PATCH] net: count hw_addr syncs so that unsync works properly.

[PATCH] net: count hw_addr syncs so that unsync works properly.

[Vlad Yasevich]

A few drivers use dev_uc_sync/unsync to synchronize the
address lists from master down to slave/lower devices.  In
some cases (bond/team) a single address list is synched down
to multiple devices.  At the time of unsync, we have a leak
in these lower devices, because "synced" is treated as a
boolean and the address will not be unsynced for anything after
the fist device/call.

Treat "synced" as a count (same as refcount) and allow all
unsync calls to work.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
---
 include/linux/netdevice.h | 2 +-
 net/core/dev_addr_lists.c | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8bfa956..6151e90 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -210,9 +210,9 @@ struct netdev_hw_addr {
 #define NETDEV_HW_ADDR_T_SLAVE		3
 #define NETDEV_HW_ADDR_T_UNICAST	4
 #define NETDEV_HW_ADDR_T_MULTICAST	5
-	bool			synced;
 	bool			global_use;
 	int			refcount;
+	int			synced;
 	struct rcu_head		rcu_head;
 };
 
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index bd2eb9d..abdc9e6 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -37,7 +37,7 @@ static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
 	ha->type = addr_type;
 	ha->refcount = 1;
 	ha->global_use = global;
-	ha->synced = false;
+	ha->synced = 0;
 	list_add_tail_rcu(&ha->list, &list->list);
 	list->count++;
 
@@ -165,7 +165,7 @@ int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
 					    addr_len, ha->type);
 			if (err)
 				break;
-			ha->synced = true;
+			ha->synced++;
 			ha->refcount++;
 		} else if (ha->refcount == 1) {
 			__hw_addr_del(to_list, ha->addr, addr_len, ha->type);
@@ -186,7 +186,7 @@ void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
 		if (ha->synced) {
 			__hw_addr_del(to_list, ha->addr,
 				      addr_len, ha->type);
-			ha->synced = false;
+			ha->synced--;
 			__hw_addr_del(from_list, ha->addr,
 				      addr_len, ha->type);
 		}
-- 
1.8.1.4

Re: [PATCH] net: count hw_addr syncs so that unsync works properly.

[David Miller]

From: Vlad Yasevich <vyasevic@redhat.com>
Date: Tue,  2 Apr 2013 17:10:07 -0400

> A few drivers use dev_uc_sync/unsync to synchronize the
> address lists from master down to slave/lower devices.  In
> some cases (bond/team) a single address list is synched down
> to multiple devices.  At the time of unsync, we have a leak
> in these lower devices, because "synced" is treated as a
> boolean and the address will not be unsynced for anything after
> the fist device/call.
> 
> Treat "synced" as a count (same as refcount) and allow all
> unsync calls to work.
> 
> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>

Applied and queued up for -stable, thanks Vlad.