path: root/net/core/dev.c
diff options
authorLoic Prylli <loicp@google.com>2014-07-01 21:39:43 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-28 08:06:00 -0700
commit3dc0c70ff2c78f2ba57692d4c88d39522c972ba6 (patch)
treeac0b4b4488dab989a196c925a452021d6c3ffa0c /net/core/dev.c
parentef6357dd643d3cfe192973119eb6aadd6b9f5c66 (diff)
net: Fix NETDEV_CHANGE notifier usage causing spurious arp flush
[ Upstream commit 54951194656e4853e441266fd095f880bc0398f3 ] A bug was introduced in NETDEV_CHANGE notifier sequence causing the arp table to be sometimes spuriously cleared (including manual arp entries marked permanent), upon network link carrier changes. The changed argument for the notifier was applied only to a single caller of NETDEV_CHANGE, missing among others netdev_state_change(). So upon net_carrier events induced by the network, which are triggering a call to netdev_state_change(), arp_netdev_event() would decide whether to clear or not arp cache based on random/junk stack values (a kind of read buffer overflow). Fixes: be9efd365328 ("net: pass changed flags along with NETDEV_CHANGE event") Fixes: 6c8b4e3ff81b ("arp: flush arp cache on IFF_NOARP change") Signed-off-by: Loic Prylli <loicp@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core/dev.c')
1 files changed, 8 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 4c1b483f7c07..051f17d6ff75 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -148,6 +148,9 @@ struct list_head ptype_all __read_mostly; /* Taps */
static struct list_head offload_base __read_mostly;
static int netif_rx_internal(struct sk_buff *skb);
+static int call_netdevice_notifiers_info(unsigned long val,
+ struct net_device *dev,
+ struct netdev_notifier_info *info);
* The @dev_base_head list is protected by @dev_base_lock and the rtnl
@@ -1207,7 +1210,11 @@ EXPORT_SYMBOL(netdev_features_change);
void netdev_state_change(struct net_device *dev)
if (dev->flags & IFF_UP) {
- call_netdevice_notifiers(NETDEV_CHANGE, dev);
+ struct netdev_notifier_change_info change_info;
+ change_info.flags_changed = 0;
+ call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
+ &change_info.info);
rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);