The user-supplied image/name argument was interpolated unsanitized into
registry/{name}/initrd, so a name containing '../' (e.g. 'slim run
../../.ssh/authorized_keys') escaped the XDG data dir and let slim
create directories and read/write files at attacker-chosen locations.
validate_image_name now rejects empty names, '.', '..' and anything
outside [A-Za-z0-9._:-] at the registry_dir chokepoint used by both
build and run, plus a defense-in-depth containment check that the
resolved path stays under the registry root.
Fixes sec-2 from the code review.
- build: the rootless overlay mount only exists inside podman unshare's
user namespace; run the vmlinuz check/copy and the find|cpio pipeline
there, streaming cpio's stdout to the parent for gzipping (also drops
the initrd.tmp round-trip and excludes vmlinuz from the archive)
- build: unmount the image on all code paths, not just success
- run: treat timeout's exit 124 as the expected smoke-test timeout and
error on any other non-zero status (a missing qemu binary no longer
reports success)
Fixes bug-1, bug-2, bug-3 from the code review.
hulthe
marvin