Interface index is signed integer, we can pass ifm->ifi_index from userspace via netlink and create network device with negative ifindex value.
Fixes: 9c7dafbfab15 ("net: Allow to create links with given ifindex") Signed-off-by: Serhey Popovych <serhe.popov...@gmail.com> --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 8658074..dae8010 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7491,7 +7491,7 @@ int register_netdevice(struct net_device *dev) } ret = -EBUSY; - if (!dev->ifindex) + if (dev->ifindex <= 0) dev->ifindex = dev_new_index(net); else if (__dev_get_by_index(net, dev->ifindex)) goto err_uninit; -- 1.8.3.1