[PATCH v5 1/1] fs: Allow no_new_privs tasks to call chroot(2)

[Al Viro]

On Tue, Mar 30, 2021 at 11:03:10PM -0700, Kees Cook wrote:

> Regardless, I still endorse this change because it doesn't make things
> _worse_, since without this, a compromised process wouldn't need ANY
> tricks to escape a chroot because it wouldn't be in one. :) It'd be nice
> if there were some way to make future openat() calls be unable to
> resolve outside the chroot, but I view that as an enhancement.
> 
> But, as it stands, I think this makes sense and I stand by my
> Reviewed-by tag. If Al is too busy to take it, and James would rather
> not take VFS, perhaps akpm would carry it? That's where other similar
> VFS security work has landed.

Frankly, I'm less than fond of that thing, but right now I'm buried
under all kinds of crap (->d_revalidate() joy, mostly).  I'll post
a review, but for now it's very definitely does *not* get an implicit
ACK from me.