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authorPatrick McHardy <kaber@trash.net>2008-01-20 17:25:14 -0800
committerDavid S. Miller <davem@davemloft.net>2008-01-20 20:31:45 -0800
commit68365458a4252fa993b91a00f7a0b18fed399f0d (patch)
tree824b1f32ba3b955c018626127602c365f986ccfc /net
parent[AF_KEY]: Fix skb leak on pfkey_send_migrate() error (diff)
downloadlinux-dev-68365458a4252fa993b91a00f7a0b18fed399f0d.tar.xz
linux-dev-68365458a4252fa993b91a00f7a0b18fed399f0d.zip
[NET]: rtnl_link: fix use-after-free
When unregistering the rtnl_link_ops, all existing devices using the ops are destroyed. With nested devices this may lead to a use-after-free despite the use of for_each_netdev_safe() in case the upper device is next in the device list and is destroyed by the NETDEV_UNREGISTER notifier. The easy fix is to restart scanning the device list after removing a device. Alternatively we could add new devices to the front of the list to avoid having dependant devices follow the device they depend on. A third option would be to only restart scanning if dev->iflink of the next device matches dev->ifindex of the current one. For now this seems like the safest solution. With this patch, the veth rtnl_link_ops unregistration can use rtnl_link_unregister() directly since it now also handles destruction of multiple devices at once. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/rtnetlink.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e1ba26fb4bf2..fed95a323b28 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -308,9 +308,12 @@ void __rtnl_link_unregister(struct rtnl_link_ops *ops)
struct net *net;
for_each_net(net) {
+restart:
for_each_netdev_safe(net, dev, n) {
- if (dev->rtnl_link_ops == ops)
+ if (dev->rtnl_link_ops == ops) {
ops->dellink(dev);
+ goto restart;
+ }
}
}
list_del(&ops->list);