[PATCH v3 net 9/9] bridge: Prevent possible race condition in br_fdb_change_mac_address
From: Toshiaki Makita <hidden>
Date: 2014-02-07 07:48:43
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
br_fdb_change_mac_address() calls fdb_insert()/fdb_delete() without br->hash_lock. These hash list updates are racy with br_fdb_update()/br_fdb_cleanup(). Signed-off-by: Toshiaki Makita <redacted> Acked-by: Vlad Yasevich <redacted> --- net/bridge/br_fdb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 0426dff..9203d5a 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c@@ -191,6 +191,8 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) struct net_port_vlans *pv; u16 vid = 0; + spin_lock_bh(&br->hash_lock); + /* If old entry was unassociated with any port, then delete it. */ f = __br_fdb_get(br, br->dev->dev_addr, 0); if (f && f->is_local && !f->dst)
@@ -204,7 +206,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) */ pv = br_get_vlan_info(br); if (!pv) - return; + goto out; for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) { f = __br_fdb_get(br, br->dev->dev_addr, vid);
@@ -212,6 +214,8 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, vid); } +out: + spin_unlock_bh(&br->hash_lock); } void br_fdb_cleanup(unsigned long _data)
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1.8.1.2