[PATCH v3 0/5] Partially sandbox Cloud Hypervisor, crosvm, virtiofsd, and the router

[Demi Marie Obenour <demiobenour@gmail.com>]

This restricts the access of these programs to the system.  Seccomp is
not enabled, though, and the processes still run as root.  Full
sandboxing needs additional work.  In particular, Cloud Hypervisor
should receive access to VFIO devices via file descriptor passing.

D-Bus and the portal are not sandboxed.  They have full access to all
user files by design, so a breach of either is catastrophic no matter
what.   Furthermore, sandboxing them even slightly proved very
difficult.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
Changes in v3:
- Protect bus daemon and portal from other services.
- Use s6-softlimit instead of sh to set hard RLIMIT_MEMLOCK.
- Link to v2: https://spectrum-os.org/lists/archives/spectrum-devel/20251201-sandbox-v2-0-9f4e58252c2b@gmail.com

Changes in v2:
- Sandbox Cloud Hypervisor, virtiofsd, and the router
- Link to v1: https://spectrum-os.org/lists/archives/spectrum-devel/20251129-sandbox-v1-1-6dab926504d3@gmail.com

---
Demi Marie Obenour (5):
      host/rootfs: Sandbox crosvm
      host/rootfs: Sandbox router
      host/rootfs: Unshare a few more namespaces in virtiofsd
      host/rootfs: Sandbox Cloud Hypervisor
      host/rootfs: Try to protect the portal and dbus daemon

 host/rootfs/default.nix                            |  4 +--
 .../vm-services/template/data/service/dbus/run     |  1 +
 .../template/data/service/spectrum-router/run      | 19 +++++++++++--
 .../template/data/service/vhost-user-fs/run        |  2 +-
 .../template/data/service/vhost-user-gpu/run       | 29 +++++++++++++++++++
 .../image/etc/udev/rules.d/99-spectrum.rules       |  3 ++
 host/rootfs/image/usr/bin/run-vmm                  | 33 +++++++++++++++++++++-
 7 files changed, 84 insertions(+), 7 deletions(-)
---
base-commit: 36d857a937900f85b460e9b3db89cf79737bd72c
change-id: 20251129-sandbox-5a42a6a41b59

-- 
Sincerely,
Demi Marie Obenour (she/her/hers)