Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering

Al Viro
2011-05-29T18:24:31Z

On Sun, May 29, 2011 at 10:02:06AM -0700, Linus Torvalds wrote:

> And yes, it is absolutely acceptable. The only questions in my mind are
>
> - why haven't we done this long ago?
>
> - do we have the flag space?
>
> - should we do a O_NOMNT_PATH flag to do the same for mount-points?
>
> Some people worry about being confused by bind mounts etc.
>
> - do we think ".." is worthy of a flag too?
>
> or is that a "user space can damn well check that itself, even if
> it would be absolutely trivial to check in the kernel too"?
>
> Whatever. I think the NOFOLLOW_PATH one is pretty much a no-brainer.
> It's not like symlink worries are unusual.

It's not *quite* a no-brainer. Guys, please hold that one off for a while;
we have more massage to do in the area and I *really* want to get atomic
open work finished (== intents gone, revalidation vs mountpoints sanitized,
etc.) before anything else is done to fs/namie.c. OK?

And as for .. - userland can bloody well check that on its own if it cares.
Let's keep it simple, please - we already have things far too complicated
in there for my taste.