Re: [PATCHES] ImageMagick security updates without grafting

[Maxime Devos]

On Sun, 2021-03-28 at 17:37 -0400, Mark H Weaver wrote:
> Maxime Devos <maximedevos@telenet.be> writes:
> 
> > On Sat, 2021-03-27 at 20:01 -0400, Mark H Weaver wrote:
> > > [...]
> > > Maxime wrote:
> > > > What does ‘guix refresh --list-dependent imagemagick@6.9.11-48’
> > > > output now?
> > > When I last checked, it reported on the order of 2400 dependent package
> > > rebuilds.
> > 
> > I should have written imagemagick@6.9.12-4 here.
> 
> On my Guix system, after applying my recent patch set, "guix refresh -l
> imagemagick" (which refers to imagemagick@6.9.12-4) reports 603
> dependent packages.

I had a similar number (after "guix pull").  Looks good.

> I see that, according to our guidelines, since this number is greater
> than 300, it implies that updates to 'imagemagick' should not be done on
> the 'master' branch.
> 
> On the other hand, for what it's worth, on my own GNOME system, the
> number of rebuilds from my patch set was quite minimal, and *far* less
> than the number of rebuilds than I usually need to do when updating my
> system to the latest 'master' after just a few days.
> 
> I should say that I'm fully in support of having guidelines like this to
> limit the number of rebuilds on 'master'.  It's especially important to
> me since I never use substitutes, and build everything locally on my
> (rather old) Thinkpad X200.
> 
> That said, _number_ of dependent packages is not a good measure of what
> we should be trying to minimize.  I can build hundreds of 'python-*'
> packages in the time it takes to build a single package like 'webkitgtk'
> or 'icecat'.
> 
> A better measure might try to estimate the total amount of *build time*
> suffered by _all_ Guix users, as a result of updating a given package.
> That would depend on both (1) the estimated _time_ needed to build the
> dependent packages, and (2) the estimated number of users of those
> dependent packages, perhaps based on download statistics from our
> substitute servers.

That seems a good idea, but something to discuss in a new thread
(or a bug report to make sure it is not forgotten).

> > You missed a few packages:
> > in gnu/packages/mate.scm: search for "gtk-doc".
> > Also, the (gnu packages imagemagick) import seems
> > unused.
> 
> I did not attempt to comprehensively change all 'native-inputs'
> references of 'gtk-doc' to 'gtk-doc/stable'.  I stopped when the number
> of rebuilds on my own GNOME system became quite minimal.  That's why the
> summary line of commit 9dea1618755891526f708aa335b4136c1302d16e ends
> with the words "selected packages".

I have began writing a patch that changes *all* references of
gtk-doc to gtk-doc/stable (in native-inputs only).

> However, I see now that we should continue working on this, at least
> until we can update 'imagemagick' on 'master' without violating our
> guidelines.
> 
> > Looking at the package graph, many packages depend on imagemagick
> > through python-sphinx, so it may be worthwile to define a
> > python-sphinx/stable and use it instead of python-sphinx in the
> > native-inputs.
> > 
> > I suggest
> >  guix graph --type=reverse-package imagemagick@6.9.12-4 | dot -Tpdf > a.pdf
> > 
> > to find out if there are more uses for imagemagick/stable.
> 
> That's a good idea.  Would you like to work on it?

Yes.

> One thing to be very careful about is to only use 'gtk-doc/stable',
> 'dblatex/stable', and 'imagemagick/stable' in native-inputs, and
> moreover to make sure that no references to these */stable packages
> remain in any package outputs.
> 
> Of course, if any package retains references to its 'native-inputs',
> that's always a bug, but I wouldn't be surprised if such bugs exist in
> Guix.  Such bugs might be relatively harmless now (except when
> cross-compiling), but they could become a security bug if a package
> retains a reference to 'imagemagick/stable'.

I'll be careful!

> On my own system and user profile, which includes GNOME, I'm glad to
> report that I have *no* references to 'imagemagick' at all, not even to
> its newest release, and that's my strong preference.

Note to self, before I forget how to test this:

guix build $PACKAGES
# maybe guix build $PACKAGES --no-grafts?
guix graph --type=references $PACKAGES
# ^ look in output for "imagemagick".

Greetings,
Maxime.

signature.asc
Description: This is a digitally signed message part