Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.15 14/61] net: force a list_del() in unregister_netdevice_many() | Date | Tue, 24 Jun 2014 11:50:57 -0400 |
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3.15-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ 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 <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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(-)
--- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -1036,7 +1036,6 @@ static int macvlan_device_event(struct n 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. */ --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6613,6 +6613,9 @@ 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) { @@ -6622,6 +6625,7 @@ void unregister_netdevice_many(struct li rollback_registered_many(head); list_for_each_entry(dev, head, unreg_list) net_set_todo(dev); + list_del(head); } } EXPORT_SYMBOL(unregister_netdevice_many); @@ -7077,7 +7081,6 @@ static void __net_exit default_device_ex } } unregister_netdevice_many(&dev_kill_list); - list_del(&dev_kill_list); rtnl_unlock(); } --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1744,7 +1744,6 @@ static int rtnl_dellink(struct sk_buff * ops->dellink(dev, &list_kill); unregister_netdevice_many(&list_kill); - list_del(&list_kill); return 0; } --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1758,7 +1758,6 @@ void ieee80211_remove_interfaces(struct } 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);
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