From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH net v2 9/9] bridge: Prevent possible race condition in br_fdb_change_mac_address Date: Tue, 17 Dec 2013 14:39:24 -0500 Message-ID: <52B0A86C.1080800@redhat.com> References: <1387281821-21342-1-git-send-email-makita.toshiaki@lab.ntt.co.jp> <1387281821-21342-10-git-send-email-makita.toshiaki@lab.ntt.co.jp> Reply-To: vyasevic@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: Toshiaki Makita , "David S . Miller" , Stephen Hemminger , netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43792 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752629Ab3LQTja (ORCPT ); Tue, 17 Dec 2013 14:39:30 -0500 In-Reply-To: <1387281821-21342-10-git-send-email-makita.toshiaki@lab.ntt.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: On 12/17/2013 07:03 AM, Toshiaki Makita wrote: > 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 Good bug fix. Acked-by: Vlad Yasevich -vlad > --- > 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 38cd29d..05fb8da 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) >