Consume verified Ubuntu security backports in the final runtime

.github/scripts/collect-ubuntu-backport-evidence.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Only read the exact consumer and immutable bundle; execute its guard on the runner.
+set -euo pipefail
+test "$#" -eq 3
+image=$1
+sbom=$2
+evidence=$3
+bundle_image='ghcr.io/pasturestack/ubuntu-security-backports:v0.1.0@sha256:2742a3d429e4e14bc587f6dedc51ded4246cf90bbaedcd86c67d0885e32a6f2a'
+bundle_digest=${bundle_image##*@}
+[[ "$bundle_digest" =~ ^sha256:[0-9a-f]{64}$ ]]
+test -s "$sbom"
+mkdir -p "$evidence"
+scratch=$(mktemp -d)
+consumer=
+bundle=
+cleanup() {
+    if [[ -n "$consumer" ]]; then docker rm "$consumer" >/dev/null 2>&1 || true; fi
+    if [[ -n "$bundle" ]]; then docker rm "$bundle" >/dev/null 2>&1 || true; fi
+    rm -rf -- "$scratch"
+}
+trap cleanup EXIT
+consumer=$(docker create --entrypoint /bin/true "$image")
+docker cp "$consumer:/usr/share/pasturestack/security/ubuntu-backports/." "$evidence/"
+docker rm "$consumer" >/dev/null
+consumer=
+bundle=$(docker create "$bundle_image" /artifact-export-only)
+docker cp "$bundle:/out/verify-consumer-evidence.py" "$scratch/verify-consumer-evidence.py"
+docker cp "$bundle:/out/SHA256SUMS" "$scratch/bundle-SHA256SUMS"
+docker rm "$bundle" >/dev/null
+bundle=
+python3 -B "$scratch/verify-consumer-evidence.py" \
+    --evidence-dir "$evidence" --sbom "$sbom" \
+    --expected-bundle-digest "$bundle_digest" \
+    --bundle-checksums "$scratch/bundle-SHA256SUMS"

.github/workflows/release.yml

@@ -77,22 +77,34 @@ jobs:
             -v "$RUNNER_TEMP/trivy-cache:/root/.cache/trivy" \
             "$TRIVY_IMAGE" image --scanners vuln,secret \
             --exit-code 0 \
+            --format json --output /evidence/runtime-security-raw.json "$image"
+          docker run --rm \
+            -v /var/run/docker.sock:/var/run/docker.sock \
+            -v "$PWD/evidence:/evidence" \
+            -v "$RUNNER_TEMP/trivy-cache:/root/.cache/trivy" \
+            "$TRIVY_IMAGE" image --format cyclonedx \
+            --output /evidence/runtime.cdx.json "$image"
+          backports="$RUNNER_TEMP/pod-pause-image-ubuntu-backports"
+          bash .github/scripts/collect-ubuntu-backport-evidence.sh \
+            "$image" "evidence/runtime.cdx.json" "$backports" \
+            > "evidence/ubuntu-backports-verification.json"
+          tar -C "$backports" -czf "evidence/ubuntu-backports.tar.gz" .
+          docker run --rm -v "$backports:/backports:ro" \
+            -v /var/run/docker.sock:/var/run/docker.sock \
+            -v "$PWD/evidence:/evidence" \
+            -v "$RUNNER_TEMP/trivy-cache:/root/.cache/trivy" \
+            "$TRIVY_IMAGE" image --vex /backports/openvex.json --skip-db-update --scanners vuln,secret \
+            --exit-code 0 \
             --format json --output /evidence/runtime-security.json "$image"
           jq -e '[.Results[]?.Vulnerabilities[]? | select(.Severity == "CRITICAL" or .Severity == "HIGH")] | length == 0' \
             evidence/runtime-security.json >/dev/null
           jq -e '[.Results[]?.Secrets[]?] | length == 0' evidence/runtime-security.json >/dev/null
           python3 .github/scripts/enforce-runtime-vulnerabilities.py \
             --phase release \
             --repository "$GITHUB_REPOSITORY"
-          docker run --rm \
-            -v /var/run/docker.sock:/var/run/docker.sock \
-            -v "$PWD/evidence:/evidence" \
-            -v "$RUNNER_TEMP/trivy-cache:/root/.cache/trivy" \
-            "$TRIVY_IMAGE" image --format cyclonedx \
-            --output /evidence/runtime.cdx.json "$image"
           jq -e '.bomFormat == "CycloneDX" and (.components | length > 0)' \
             evidence/runtime.cdx.json >/dev/null
-          sha256sum evidence/runtime-security.json evidence/runtime.cdx.json \
+          sha256sum evidence/runtime-security-raw.json evidence/ubuntu-backports-verification.json evidence/ubuntu-backports.tar.gz evidence/runtime-security.json evidence/runtime.cdx.json \
             > evidence/SHA256SUMS
 
       - name: Publish immutable runtime image
@@ -131,7 +143,8 @@ jobs:
           gh release create "$GITHUB_REF_NAME" --repo "$GITHUB_REPOSITORY" --verify-tag \
             --title "Pod Pause Image $GITHUB_REF_NAME" \
             --notes 'Pure numeric PastureStack pod-infrastructure image release with signal smoke tests, vulnerability scan, SBOM, checksums, and provenance.' \
-            evidence/runtime-security.json evidence/runtime.cdx.json evidence/SHA256SUMS
+            evidence/runtime-security-raw.json evidence/runtime-security.json evidence/runtime.cdx.json \
+            evidence/ubuntu-backports-verification.json evidence/ubuntu-backports.tar.gz evidence/SHA256SUMS
 
       - name: Clean run-owned resources
         if: always()

.github/workflows/security-release-gate.yml

@@ -136,14 +136,28 @@ jobs:
             --volume "$PWD/evidence:/evidence" \
             --volume "$trivy_cache:/root/.cache/trivy" \
             "$TRIVY_IMAGE" image \
-            --format cyclonedx \
-            --output /evidence/image.cdx.json \
+            --scanners vuln \
+            --format json \
+            --output /evidence/image-vulnerabilities-raw.json \
             "$CANDIDATE_IMAGE"
           docker run --rm \
             --volume /var/run/docker.sock:/var/run/docker.sock \
             --volume "$PWD/evidence:/evidence" \
             --volume "$trivy_cache:/root/.cache/trivy" \
             "$TRIVY_IMAGE" image \
+            --format cyclonedx \
+            --output /evidence/image.cdx.json \
+            "$CANDIDATE_IMAGE"
+          backports="$RUNNER_TEMP/pod-pause-image-ubuntu-backports"
+          bash .github/scripts/collect-ubuntu-backport-evidence.sh \
+            "$CANDIDATE_IMAGE" "evidence/image.cdx.json" "$backports" \
+            > "evidence/ubuntu-backports-verification.json"
+          tar -C "$backports" -czf "evidence/ubuntu-backports.tar.gz" .
+          docker run --rm -v "$backports:/backports:ro" \
+            --volume /var/run/docker.sock:/var/run/docker.sock \
+            --volume "$PWD/evidence:/evidence" \
+            --volume "$trivy_cache:/root/.cache/trivy" \
+            "$TRIVY_IMAGE" image --vex /backports/openvex.json --skip-db-update \
             --scanners vuln \
             --format json \
             --output /evidence/image-vulnerabilities.json \

Dockerfile

@@ -1,5 +1,8 @@
+# syntax=docker/dockerfile:1.7
 ARG UBUNTU_IMAGE=ubuntu:26.04@sha256:2260313b31c8c011cd2eebe728008efac1b3982be73eb71348ea2648d2c0e09b
 
+ARG UBUNTU_SECURITY_BACKPORTS_IMAGE=ghcr.io/pasturestack/ubuntu-security-backports:v0.1.0@sha256:2742a3d429e4e14bc587f6dedc51ded4246cf90bbaedcd86c67d0885e32a6f2a
+
 FROM ${UBUNTU_IMAGE} AS snapshot-ca-bootstrap
 
 ADD --checksum=sha256:5b6326f1932cfd7be57130561dc78192f09ed9f58bfbe6606ed0c50510c3b6cd \
@@ -84,9 +87,12 @@ RUN gcc -O2 -Wall -Wextra -Werror -D_FORTIFY_SOURCE=3 -fstack-protector-strong -
         -Wl,-z,relro -Wl,-z,now -Wl,--build-id=none -o /out-pause pause.c \
     && strip /out-pause
 
+FROM ${UBUNTU_SECURITY_BACKPORTS_IMAGE} AS ubuntu_security_backports
+
 FROM ${UBUNTU_IMAGE}
+ARG UBUNTU_SECURITY_BACKPORTS_IMAGE
 
-ARG IMAGE_VERSION=v3.0.5
+ARG IMAGE_VERSION=v3.0.6
 ARG SOURCE_REVISION=unknown
 ARG UBUNTU_IMAGE
 
@@ -120,5 +126,24 @@ COPY --from=build /out-pause /pause
 COPY --from=build /usr/share/pasturestack/manifests/ /usr/share/pasturestack/manifests/
 COPY LICENSE /usr/share/licenses/pod-pause-image/LICENSE
 
+# Keep the build-only installer and package archives outside the final image.
+RUN --mount=type=bind,from=ubuntu_security_backports,source=/out,target=/opt/pasturestack/ubuntu-security-backports,readonly \
+    set -eux; \
+    evidence=/usr/share/pasturestack/security/ubuntu-backports; \
+    mkdir -p "$evidence"; \
+    /opt/pasturestack/ubuntu-security-backports/install-existing-backports --install-in-docker-build > "$evidence/install.json"; \
+    /opt/pasturestack/ubuntu-security-backports/install-existing-backports --verify-installed > "$evidence/verify.json"; \
+    for file in manifest.json qualification.json source-inputs.lock.json openvex.json; do \
+        cp "/opt/pasturestack/ubuntu-security-backports/$file" "$evidence/$file"; \
+    done; \
+    printf '%s\n' "$UBUNTU_SECURITY_BACKPORTS_IMAGE" > "$evidence/bundle-image.txt"; \
+    (cd "$evidence" && sha256sum manifest.json qualification.json source-inputs.lock.json openvex.json install.json verify.json bundle-image.txt > SHA256SUMS); \
+    { \
+        printf 'record\tname\tarchitecture\tversion\n'; \
+        printf 'metadata\tschema\t-\tpasturestack.dpkg-manifest/v1\n'; \
+        printf 'metadata\tbase_image\t-\t%s\n' "$UBUNTU_IMAGE"; \
+        dpkg-query -W -f='package\t${binary:Package}\t${Architecture}\t${Version}\n' | LC_ALL=C sort; \
+    } > /usr/share/pasturestack/manifests/runtime-ubuntu-packages.tsv
+
 USER 65532:65532
 ENTRYPOINT ["/pause"]

README.md

@@ -1,5 +1,9 @@
 # PastureStack Pod Pause Image
 
+Linux runtime **`v3.0.6`** consumes verified Ubuntu security backports without adding packages or changing the existing coreutils provider.
+
+The runtime recipe applies the qualified Ubuntu 26.04 backport bundle only to already-installed packages and preserves the selected coreutils provider. The immutable bundle digest and final-image checks are pending. Bundle manifests, qualification, exact-version OpenVEX, source inputs and install/verify receipts are retained under `/usr/share/pasturestack/security/ubuntu-backports/`; raw scan evidence and the existing full-severity release policy remain required.
+
 A small pod-infrastructure image that keeps a container alive, reaps orphaned child processes, and exits cleanly when it receives `SIGTERM` or `SIGINT`.
 
 PastureStack is an independent community effort to preserve, audit, and modernize the Rancher 1.6 ecosystem. It is not affiliated with or endorsed by Rancher Labs or SUSE.
@@ -8,10 +12,10 @@ PastureStack is an independent community effort to preserve, audit, and moderniz
 
 ## Maintained image
 
-The reviewed `linux/amd64` runtime uses the pure numeric coordinate:
+After publication, the candidate `linux/amd64` runtime uses the pure numeric coordinate:
 
 ```text
-ghcr.io/pasturestack/pod-pause-image:v3.0.5
+ghcr.io/pasturestack/pod-pause-image:v3.0.6
 ```
 
 Product identity and provenance are carried by the package name, OCI labels,
@@ -21,7 +25,7 @@ numeric successor after its release and integration gates pass.
 
 ## Build
 
-Version 3.0.5 installs the SHA256-pinned official Ubuntu CA security update in
+The recipe installs the SHA256-pinned official Ubuntu CA security update in
 the build stage after the locked snapshot. Both stages apply the existing-package
 security micro-updates in `ubuntu-security-packages.lock` from the signed
 2026-10-23 Ubuntu 26.04 snapshot, without adding or removing packages. This
@@ -33,9 +37,9 @@ signal-handling, privilege or pod-sandbox behavior.
 
 ```sh
 docker build --pull \
-  --build-arg IMAGE_VERSION=v3.0.5 \
+  --build-arg IMAGE_VERSION=v3.0.6 \
   --build-arg SOURCE_REVISION="$(git rev-parse HEAD)" \
-  -t local/pasturestack/pod-pause-image:v3.0.5 .
+  -t local/pasturestack/pod-pause-image:v3.0.6 .
 ```
 
 The runtime base is pinned to the reviewed Ubuntu 26.04 `linux/amd64` manifest. The build stage uses the HTTPS Ubuntu snapshot and exact direct-package versions recorded in [`ubuntu-apt.lock`](ubuntu-apt.lock). The final image carries the resolved builder toolchain, builder package, and runtime package manifests under `/usr/share/pasturestack/manifests/`; CI also records builder and runtime image inspections, CycloneDX SBOMs, vulnerability reports, and signal-handling smoke tests as a 30-day review artifact.
@@ -45,7 +49,7 @@ The release gate checks the complete runtime vulnerability report. Any available
 ## Smoke test
 
 ```sh
-docker run -d --name pod-pause-poc local/pasturestack/pod-pause-image:v3.0.5
+docker run -d --name pod-pause-poc local/pasturestack/pod-pause-image:v3.0.6
 docker inspect --format '{{.State.Running}} {{.Config.User}}' pod-pause-poc
 docker stop --time 5 pod-pause-poc
 docker inspect --format '{{.State.ExitCode}}' pod-pause-poc

scripts/validate

@@ -45,7 +45,7 @@ grep -F 'builder-ubuntu-packages.tsv' Dockerfile >/dev/null
 grep -F 'builder-toolchain.tsv' Dockerfile >/dev/null
 grep -F 'runtime-ubuntu-packages.tsv' Dockerfile >/dev/null
 grep -F 'rm -f /usr/bin/pebble' Dockerfile >/dev/null
-grep -F 'ARG IMAGE_VERSION=v3.0.5' Dockerfile >/dev/null
+grep -F 'ARG IMAGE_VERSION=v3.0.6' Dockerfile >/dev/null
 grep -F 'ADD --checksum=sha256:5b6326f1932cfd7be57130561dc78192f09ed9f58bfbe6606ed0c50510c3b6cd' Dockerfile >/dev/null
 grep -F 'https://archive.ubuntu.com/ubuntu/pool/main/c/ca-certificates/ca-certificates_20260816ubuntu0.26.04.1_all.deb' Dockerfile >/dev/null
 test "$(grep -Fc 'dpkg -i /tmp/ca-certificates.deb;' Dockerfile)" -eq 1