Subject: Re: [PATCH] netns: avoid directory traversal (was: ip netns: Make sure netns name is sane)

From: Stephen Hemminger <[email-masked]>
Date: Tue, 18 Jul 2017 17:12:30 -0700

On Mon, 10 Jul 2017 14:08:31 +0200
Matteo Croce <[email-masked]> wrote:

> Hi Phil,
> 
> I noticed that your patch still leaves an uncovered scenario, the one where the
> namespace name is "." or "..".
> Calling 'ip netns del ..' will remove /var/run which is a symlink to /run on
> most systems causing some daemons, eg. dbus, to fail.
> 
> ip netns doesn't validate input, allowing creation and deletion of files
> relatives to /var/run/netns.
> This patch denies creation or deletion of namespaces with names contaning
> "/" or that matches exactly "." or "..".
> ---
>  ip/ipnetns.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 

The patch itself is good, but the commit message needs fixing.
Please rewrite it to describe the problem, and add signed-off-by