Re: [PATCH net v2 1/5] net: fix ifname in netlink ntf during netns move

[Jiri Pirko <jiri@resnulli.us>]

Wed, Oct 18, 2023 at 05:13:41PM CEST, kuba@kernel.org wrote:
>On Wed, 18 Oct 2023 09:12:58 +0200 Jiri Pirko wrote:
>> >+static int dev_prep_valid_name(struct net *net, struct net_device *dev,
>> >+			       const char *want_name, char *out_name)
>> >+{
>> >+	int ret;
>> >+
>> >+	if (!dev_valid_name(want_name))
>> >+		return -EINVAL;
>> >+
>> >+	if (strchr(want_name, '%')) {
>> >+		ret = __dev_alloc_name(net, want_name, out_name);
>> >+		return ret < 0 ? ret : 0;
>> >+	} else if (netdev_name_in_use(net, want_name)) {
>> >+		return -EEXIST;
>> >+	} else if (out_name != want_name) {  
>> 
>> How this can happen?
>> You call dev_prep_valid_name() twice:
>> 	ret = dev_prep_valid_name(net, dev, name, buf);
>> 	err = dev_prep_valid_name(net, dev, pat, new_name);
>> 
>> Both buf and new_name are on stack tmp variables.
>
>I'm moving this code 1-to-1. I have patches queued up to clean all 
>this up in net-next. Please let me know if you see any bugs.

Okay, fair enough. It just looks odd, but I get it for "net".

Reviewed-by: Jiri Pirko <jiri@nvidia.com>