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>
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>
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>
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>
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>
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>
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>
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>
