Re: fs_context-related oops in mainline

[Greg Kroah-Hartman]

On Fri, Mar 15, 2019 at 02:24:30PM +0000, David Howells wrote:
> Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > -	if (fc->user_ns)
> > -		put_user_ns(fc->user_ns);
> > -	fc->user_ns = get_user_ns(netns->user_ns);
> > +	if (netns) {
> > +		if (fc->user_ns)
> > +			put_user_ns(fc->user_ns);
> > +		fc->user_ns = get_user_ns(netns->user_ns);
> > +	}
> 
> This begs the question why is sysfs using the current network namespace's idea
> of the user namespace?  Why not just use the one directly from current->cred?

Ask the networking people that question, I have no idea :)