Re: [PATCH] namei: Fix use after free in kern_path_locked

[Dmitry Kadashev]

On Wed, Sep 1, 2021 at 4:13 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 01, 2021 at 02:35:08PM +0700, Dmitry Kadashev wrote:
> > Ouch. Thanks for taking care of this, Stephen. I guess
> > filename_parentat() should be killed, since kern_path_locked() was the
> > only place it's used in and it always results in danging "last",
> > provoking bugs just like this one. I can send a patch on top of this if
> > you prefer.
>
> Yes.  And then rename __filename_parentat to filename_parentat, please.

I see why you want it to be renamed - and I'll send the patch.  The only
problem I have with the rename is with __filename_parentat() there is a
nice uniformity: filename_* functions consume the passed name, and
__filename_* do not. So maybe it's something nice to have. Maybe not.

Anyway, as I've mentioned, I'll send the patch and it can be either
picked up or ignored.

-- 
Dmitry