Preserve cleanup after daemon restarts and harden OCI and tar imports
against filenames that debugfs cannot encode safely.
Mirror tap, loop, and dm teardown identity onto VM.Runtime, teach
cleanup and reconcile to fall back to those persisted fields when
handles.json is missing or corrupt, and clear the recovery state on
stop, error, and delete paths.
Reject debugfs-hostile entry names during flattening and in
ApplyOwnership itself, then add regression coverage for corrupt
handles.json recovery and unsafe import paths.
Verified with targeted go tests, make lint-go, make lint-shell, and
make build.
imagepull.Flatten now captures per-file uid/gid/mode/type from the
tar headers as it walks layers, returning a Metadata map alongside
the extracted tree. Whiteouts correctly drop the victim's metadata.
The returned Metadata feeds the new imagepull.ApplyOwnership, which
pipes a batched `set_inode_field` script to `debugfs -w -f -`.
Why: mkfs.ext4 -d copies the runner's on-disk uids verbatim, so
without this pass setuid binaries become setuid-nonroot and sshd
refuses to start on the resulting image. With the pass, a pulled
debian:bookworm has /usr/bin/sudo with uid=0 + setuid bit surviving
intact.
imagepull.BuildExt4 signature unchanged; ownership is applied as a
separate step by the daemon orchestrator between BuildExt4 and
StageBootArtifacts, keeping each helper focused. The seam
(d.pullAndFlatten) now returns (Metadata, error) for test stubs to
feed synthetic metadata.
StdinRunner is a new duck-typed extension next to CommandRunner;
the real system.Runner implements RunStdin, test mocks don't need
to unless they exercise stdin. Prevents every existing mock from
growing a new method.
Tests:
- TestFlattenCapturesHeaderMetadata: setuid bit + mode survive the
tar-header walk
- TestApplyOwnershipRewritesUidGidMode: real debugfs round-trip —
create ext4 with runner's uid, apply synthetic metadata setting
uid=0 + setuid mode, verify via `debugfs -R stat` that the
inode now has uid=0 and mode 04755
- TestBuildOwnershipScriptDeterministic: sorted, well-formed
sif script output
Debugfs and mkfs.ext4 tests skip if the binaries aren't on PATH.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
