fix(ci): supply-chain-audit uses two-dot diff, causing false positives on stale-branch PRs

The workflow diffs base.sha..head.sha (two-dot), which compares the
tip-of-main tree directly against the PR tip. When files land on main
after a PR branched off, they appear in the diff even though the PR
never touched them — triggering false-positive findings.

Example: PR #30609 was flagged for hermes_cli/setup.py, a file added
to main by an unrelated commit after the PR branched.

Switch to three-dot diff (base.sha...head.sha), which diffs from the
merge base to the PR tip — only changes introduced by this PR are
included. Applied to all four diff commands in both jobs (scan and
dep-bounds).
This commit is contained in:
ethernet 2026-05-22 17:50:56 -04:00 committed by Teknium
parent 2233b8b244
commit 2f320cb35a

View file

@ -47,14 +47,17 @@ jobs:
HEAD="${{ github.event.pull_request.head.sha }}"
# Added lines only, excluding lockfiles.
DIFF=$(git diff "$BASE".."$HEAD" -- . ':!uv.lock' ':!*.lock' ':!package-lock.json' ':!yarn.lock' || true)
# Three-dot diff (base...head) diffs from the merge base to HEAD,
# so only changes introduced by this PR are included — not changes
# that landed on main after the PR branched off.
DIFF=$(git diff "$BASE"..."$HEAD" -- . ':!uv.lock' ':!*.lock' ':!package-lock.json' ':!yarn.lock' || true)
FINDINGS=""
# --- .pth files (auto-execute on Python startup) ---
# The exact mechanism used in the litellm supply chain attack:
# https://github.com/BerriAI/litellm/issues/24512
PTH_FILES=$(git diff --name-only "$BASE".."$HEAD" | grep '\.pth$' || true)
PTH_FILES=$(git diff --name-only "$BASE"..."$HEAD" | grep '\.pth$' || true)
if [ -n "$PTH_FILES" ]; then
FINDINGS="${FINDINGS}
### 🚨 CRITICAL: .pth file added or modified
@ -97,7 +100,7 @@ jobs:
# --- Install-hook files (setup.py/sitecustomize/usercustomize/__init__.pth) ---
# These execute during pip install or interpreter startup.
SETUP_HITS=$(git diff --name-only "$BASE".."$HEAD" | grep -E '(^|/)(setup\.py|setup\.cfg|sitecustomize\.py|usercustomize\.py|__init__\.pth)$' || true)
SETUP_HITS=$(git diff --name-only "$BASE"..."$HEAD" | grep -E '(^|/)(setup\.py|setup\.cfg|sitecustomize\.py|usercustomize\.py|__init__\.pth)$' || true)
if [ -n "$SETUP_HITS" ]; then
FINDINGS="${FINDINGS}
### 🚨 CRITICAL: Install-hook file added or modified
@ -158,7 +161,7 @@ jobs:
HEAD="${{ github.event.pull_request.head.sha }}"
# Only check added lines in pyproject.toml
ADDED=$(git diff "$BASE".."$HEAD" -- pyproject.toml | grep '^+' | grep -v '^+++' || true)
ADDED=$(git diff "$BASE"..."$HEAD" -- pyproject.toml | grep '^+' | grep -v '^+++' || true)
if [ -z "$ADDED" ]; then
echo "found=false" >> "$GITHUB_OUTPUT"