From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933029AbaHHUx2 (ORCPT ); Fri, 8 Aug 2014 16:53:28 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41250 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932981AbaHHUxP (ORCPT ); Fri, 8 Aug 2014 16:53:15 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.13 220/259] net: force a list_del() in unregister_netdevice_many() Date: Fri, 8 Aug 2014 13:40:43 -0700 Message-Id: <1407530482-4483-221-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407530482-4483-1-git-send-email-kamal@canonical.com> References: <1407530482-4483-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 87757a917b0b3c0787e0563c679762152be81312 ] unregister_netdevice_many() API is error prone and we had too many bugs because of dangling LIST_HEAD on stacks. See commit f87e6f47933e3e ("net: dont leave active on stack LIST_HEAD") In fact, instead of making sure no caller leaves an active list_head, just force a list_del() in the callee. No one seems to need to access the list after unregister_netdevice_many() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/net/macvlan.c | 1 - net/core/dev.c | 5 ++++- net/core/rtnetlink.c | 1 - net/mac80211/iface.c | 1 - 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 9687122..333f8bc 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -1052,7 +1052,6 @@ static int macvlan_device_event(struct notifier_block *unused, list_for_each_entry_safe(vlan, next, &port->vlans, list) vlan->dev->rtnl_link_ops->dellink(vlan->dev, &list_kill); unregister_netdevice_many(&list_kill); - list_del(&list_kill); break; case NETDEV_PRE_TYPE_CHANGE: /* Forbid underlaying device to change its type. */ diff --git a/net/core/dev.c b/net/core/dev.c index fd9b17a..9e8b117 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6477,6 +6477,9 @@ EXPORT_SYMBOL(unregister_netdevice_queue); /** * unregister_netdevice_many - unregister many devices * @head: list of devices + * + * Note: As most callers use a stack allocated list_head, + * we force a list_del() to make sure stack wont be corrupted later. */ void unregister_netdevice_many(struct list_head *head) { @@ -6486,6 +6489,7 @@ void unregister_netdevice_many(struct list_head *head) rollback_registered_many(head); list_for_each_entry(dev, head, unreg_list) net_set_todo(dev); + list_del(head); } } EXPORT_SYMBOL(unregister_netdevice_many); @@ -6941,7 +6945,6 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list) } } unregister_netdevice_many(&dev_kill_list); - list_del(&dev_kill_list); rtnl_unlock(); } diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 17833d1..410e586 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1673,7 +1673,6 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh) ops->dellink(dev, &list_kill); unregister_netdevice_many(&list_kill); - list_del(&list_kill); return 0; } diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index a075791..822d508 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1774,7 +1774,6 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local) } mutex_unlock(&local->iflist_mtx); unregister_netdevice_many(&unreg_list); - list_del(&unreg_list); list_for_each_entry_safe(sdata, tmp, &wdev_list, list) { list_del(&sdata->list); -- 1.9.1