Re: [GIT PULL] Keys: Set 4 - Key ACLs for 5.3

[Eric Biggers]

On Wed, Jul 10, 2019 at 12:46:22PM -0700, Eric Biggers wrote:
> On Wed, Jul 10, 2019 at 11:35:07AM -0700, Linus Torvalds wrote:
> > On Fri, Jul 5, 2019 at 2:30 PM David Howells <dhowells@xxxxxxxxxx> wrote:
> > >
> > > Here's my fourth block of keyrings changes for the next merge window.  They
> > > change the permissions model used by keys and keyrings to be based on an
> > > internal ACL by the following means:
> > 
> > It turns out that this is broken, and I'll probably have to revert the
> > merge entirely.
> > 
> > With this merge in place, I can't boot any of the machines that have
> > an encrypted disk setup. The boot just stops at
> > 
> >   systemd[1]: Started Forward Password Requests to Plymouth Directory Watch.
> >   systemd[1]: Reached target Paths.
> > 
> > and never gets any further. I never get the prompt for a passphrase
> > for the disk encryption.
> > 
> > Apparently not a lot of developers are using encrypted volumes for
> > their development machines.
> > 
> > I'm not sure if the only requirement is an encrypted volume, or if
> > this is also particular to a F30 install in case you need to be able
> > to reproduce. But considering that you have a redhat email address,
> > I'm sure you can find a F30 install somewhere with an encrypted disk.
> > 
> > David, if you can fix this quickly, I'll hold off on the revert of it
> > all, but I can wait only so long. I've stopped merging stuff since I
> > noticed my machines don't work (this merge window has not been
> > pleasant so far - in addition to this issue I had another entirely
> > unrelated boot failure which made bisecting this one even more fun).
> > 
> > So if I don't see a quick fix, I'll just revert in order to then
> > continue to do pull requests later today. Because I do not want to do
> > further pulls with something that I can't boot as a base.
> > 
> >                  Linus
> 
> This also broke 'keyctl new_session' and hence all the fscrypt tests
> (https://lkml.kernel.org/lkml/20190710011559.GA7973@xxxxxxxxxxxxxxx/), and it
> also broke loading in-kernel X.509 certificates
> (https://lore.kernel.org/lkml/27671.1562384658@turing-police/T/#u).
> 
> I'm *guessing* these are all some underlying issue where keyrings aren't being
> given all the needed permissions anymore.
> 
> But just FYI, David had said he's on vacation with no laptop or email access for
> 2 weeks starting from Sunday (3 days ago).  So I don't think you can expect a
> quick fix from him.
> 
> I was planning to look into this to fix the fscrypt tests, but it might be a few
> days before I get to it.  And while I'm *guessing* it will be a simple fix, it
> might not be.  So I can't speak for David, but personally I'm fine with the
> commits being reverted for now.
> 
> I'm also unhappy that the new keyctl KEYCTL_GRANT_PERMISSION doesn't have any
> documentation or tests.  (Which seems to be a common problem with David's
> work...  None of the new mount syscalls in v5.2 have any tests, for example, and
> the man pages are still work-in-progress and last sent out for review a year
> ago, despite API changes that occurred before the syscalls were merged.)
> 

Also worth noting that the key ACL patches were only in linux-next for 9 days
before the pull request was sent.  The X.509 certificate loading bug (which
might be the same underlying bug) was reported on July 6 by someone testing
linux-next, but the pull request had already been sent on July 5.  I suspect
these bug(s) would have been fixed if they had been in linux-next for longer.

- Eric