Commit graph

15 commits

Author SHA1 Message Date
Maxime Bélair
3ff3a8a467 apparmor: Fix passt abstraction
Commit b686afa2 introduced the invalid apparmor rule
`mount options=(rw, runbindable) /,` since runbindable mount rules
cannot have a source.

Therefore running aa-logprof/aa-genprof will trigger errors (see
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685)

    $ sudo aa-logprof
    ERROR: Operation {'runbindable'} cannot have a source. Source = AARE('/')

This patch fixes it to the intended behavior.

Link: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685
Fixes: b686afa23e ("apparmor: Explicitly pass options we use while remounting root filesystem")
Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-05-22 23:16:27 +02:00
Paul Holzinger
6cdc9fd51b apparmor: allow netns paths on /tmp
For some unknown reason "owner" makes it impossible to open bind mounted
netns references as apparmor denies it. In the kernel denied log entry
we see ouid=0 but it is not clear why that is as the actual file is
owned by the real (rootless) user id.

In abstractions/pasta there is already `@{run}/user/@{uid}/**` without
owner set for the same reason as this path contains the netns path by
default when running under Podman.

Fixes: 72884484b0 ("apparmor: allow read access on /tmp for pasta")
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-05-13 23:02:18 +02:00
Paul Holzinger
72884484b0 apparmor: allow read access on /tmp for pasta
The podman CI on debian runs tests based on /tmp but pasta is failing
there because it is unable to open the netns path as the open for read
access is denied.

Link: https://github.com/containers/podman/issues/22625
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-05-10 16:53:35 +02:00
Danish Prakash
88c2f08eba apparmor: Fix access to procfs namespace entries in pasta's abstraction
From an original patch by Danish Prakash.

With commit ff22a78d7b ("pasta: Don't try to watch namespaces in
procfs with inotify, use timer instead"), if a filesystem-bound
target namespace is passed on the command line, we'll grab a handle
on its parent directory. That commit, however, didn't introduce a
matching AppArmor rule. Add it here.

To access a network namespace procfs entry, we also need a 'ptrace'
rule. See commit 594dce66d3 ("isolation: keep CAP_SYS_PTRACE when
required") for details as to when we need this -- essentially, it's
about operation with Buildah.

Reported-by: Jörg Sonnenberger <joerg@bec.de>
Link: https://github.com/containers/buildah/issues/5440
Link: https://bugzilla.suse.com/show_bug.cgi?id=1221840
Fixes: ff22a78d7b ("pasta: Don't try to watch namespaces in procfs with inotify, use timer instead")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-04-05 12:12:26 +02:00
Stefano Brivio
100919ce74 apparmor: Expand scope of @{run}/user access, allow writing PID files too
With Podman's custom networks, pasta will typically need to open the
target network namespace at /run/user/<UID>/containers/networks:
grant access to anything under /run/user/<UID> instead of limiting it
to some subpath.

Note that in this case, Podman will need pasta to write out a PID
file, so we need write access, for similar locations, too.

Reported-by: Jörg Sonnenberger <joerg@bec.de>
Link: https://github.com/containers/buildah/issues/5440
Link: https://bugzilla.suse.com/show_bug.cgi?id=1221840
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-04-05 12:12:26 +02:00
Stefano Brivio
dc7b7f28b7 apparmor: Add mount rule with explicit, empty source in passt abstraction
For the policy to work as expected across either AppArmor commit
9d3f8c6cc05d ("parser: fix parsing of source as mount point for
propagation type flags") and commit 300889c3a4b7 ("parser: fix option
flag processing for single conditional rules"), we need one mount
rule with matching mount options as "source" (that is, without
source), and one without mount options and an explicit, empty source.

Link: https://github.com/containers/buildah/issues/5440
Link: https://bugzilla.suse.com/show_bug.cgi?id=1221840
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-04-05 12:12:26 +02:00
Stefano Brivio
63a8302961 apparmor: Add pasta's own profile
If pasta and pasta.avx2 are hard links to passt and passt.avx2,
AppArmor will attach their own profiles on execution, and we can
restrict passt's profile to what it actually needs. Note that pasta
needs to access all the resources that passt needs, so the pasta
abstraction still includes passt's one.

I plan to push the adaptation required for the Debian package in
commit 5bb812e79143 ("debian/rules: Override pasta symbolic links
with hard links"), on Salsa. If other distributions need to support
AppArmor profiles they can follow a similar approach.

The profile itself will be installed, there, via dh_apparmor, in a
separate commit, b52557fedcb1 ("debian/rules: Install new pasta
profile using dh_apparmor").

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-09-07 00:31:35 +02:00
Stefano Brivio
abf5ef6c22 apparmor: Allow pasta to remount /proc, access entries under its own copy
Since commit b0e450aa85 ("pasta: Detach mount namespace, (re)mount
procfs before spawning command"), we need to explicitly permit mount
of /proc, and access to entries under /proc/PID/net (after remount,
that's what AppArmor sees as path).

Fixes: b0e450aa85 ("pasta: Detach mount namespace, (re)mount procfs before spawning command")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-09-07 00:31:35 +02:00
Stefano Brivio
e2ad420fa2 apparmor: Allow read-only access to uid_map
Starting with commit 770d1a4502 ("isolation: Initially Keep
CAP_SETFCAP if running as UID 0 in non-init"), the lack of this rule
became more apparent as pasta needs to access uid_map in procfs even
as non-root.

However, both passt and pasta needs this, in case they are started as
root, so add this directly to passt's abstraction (which is sourced
by pasta's profile too).

Fixes: 770d1a4502 ("isolation: Initially Keep CAP_SETFCAP if running as UID 0 in non-init")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-09-07 00:31:35 +02:00
Stefano Brivio
b686afa23e apparmor: Explicitly pass options we use while remounting root filesystem
As a result of AppArmor commit d4b0fef10a4a ("parser: fix rule flag
generation change_mount type rules"), we can't expect anymore to
get permission to mount() / read-write, with MS_REC | MS_UNBINDABLE
("runbindable", in AppArmor terms), if we don't explicitly pass those
flags as options. It used to work by mistake.

Now, the reasonable expectation would be that we could just change the
existing rule into:

  mount options=(rw, runbindable) "" -> /,

...but this now fails to load too, I think as a result of AppArmor
commit 9d3f8c6cc05d ("parser: fix parsing of source as mount point
for propagation type flags"). It works with 'rw' alone, but
'runbindable' is indeed a propagation type flag.

Skip the source specification, it doesn't add anything meaningful to
the rule anyway.

Reported-by: Paul Holzinger <pholzing@redhat.com>
Link: https://github.com/containers/podman/pull/19751
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-09-07 00:31:22 +02:00
Stefano Brivio
6d3e426d2f apparmor: Use abstractions/nameservice to deal with symlinked resolv.conf
While abstractions/nameservice appeared too broad and overkill for
our simple need (read-only resolv.conf access), it properly deals
with symlinked resolv.conf files generated by systemd-resolved,
NetworkManager or suchlike.

If we just grant read-only access to /etc/resolv.conf, we'll fail to
read nameserver information in rather common configurations, because
AppArmor won't follow the symlink.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-09-06 20:39:12 +02:00
Stefano Brivio
ca2749e1bd passt: Relicense to GPL 2.0, or any later version
In practical terms, passt doesn't benefit from the additional
protection offered by the AGPL over the GPL, because it's not
suitable to be executed over a computer network.

Further, restricting the distribution under the version 3 of the GPL
wouldn't provide any practical advantage either, as long as the passt
codebase is concerned, and might cause unnecessary compatibility
dilemmas.

Change licensing terms to the GNU General Public License Version 2,
or any later version, with written permission from all current and
past contributors, namely: myself, David Gibson, Laine Stump, Andrea
Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian
Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-04-06 18:00:33 +02:00
Stefano Brivio
b1b75bd73a contrib/apparmor: Split profile into abstractions, use them
One day, libvirt might actually support running passt to provide
guest connectivity. Should libvirtd (or virtqemud) start passt, it
will need to access socket and PID files in specific locations, and
passt needs to accept SIGTERM in case QEMU fails to start after passt
is already started.

To make this more convenient, split the current profile into two
abstractions, for passt and for pasta, so that external programmes
can include the bits they need (and especially not include the pasta
abstraction if they only need to start passt), plus whatever specific
adaptation is needed.

For stand-alone usage of passt and pasta, the 'passt' profile simply
includes both abstractions, plus rules to create and access PID and
capture files in default or reasonable ($HOME) locations.

Tested on Debian with libvirt 9.0.0 together with a local fix to start
passt as intended, namely libvirt commit c0efdbdb9f66 ("qemu_passt:
Avoid double daemonizing passt"). This is an example of how the
libvirtd profile (or virtqemud abstraction, or virtqemud profile) can
use this:

  # support for passt network back-end
  /usr/bin/passt Cx -> passt,
  profile passt {
    /usr/bin/passt r,

    owner @{run}/user/[0-9]*/libvirt/qemu/run/passt/* rw,
    signal (receive) set=("term") peer=/usr/sbin/libvirtd,
    signal (receive) set=("term") peer=libvirtd,

    include if exists <abstractions/passt>
  }

translated:

- when executing /usr/bin/passt, switch to the subprofile "passt"
  (not the "discrete", i.e. stand-alone profile), described below.
  Scrub the environment (e.g. LD_PRELOAD is dropped)

- in the "passt" subprofile:

  - allow reading the binary

  - allow read and write access to PID and socket files

  - make passt accept SIGTERM from /usr/sbin/libvirtd, and
    libvirtd peer names

  - include anything else that's needed by passt itself

Suggested-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-27 18:56:32 +01:00
Stefano Brivio
fb7b71b86f contrib/apparmor: Merge pasta and passt profiles, update rules
AppArmor resolves executable links before profile attachment rules
are evaluated, so, as long as pasta is installed as a link to passt,
there's no way to differentiate the two cases. Merge the two profiles
and leave a TODO note behind, explaining two possible ways forward.

Update the rules so that passt and pasta are actually usable, once
the profile is installed. Most required changes are related to
isolation and sandboxing features.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-11-16 15:11:07 +01:00
Stefano Brivio
e9d573b14f passt, pasta: Add examples of AppArmor policies
These should cover any reasonably common use case in distributions.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-03-29 15:35:38 +02:00