From 2ee3470627deae0ad11adf8c76bb6b8a1cd3619c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aur=C3=A9lien=20Bombo?= <abombo@microsoft.com>
Date: Mon, 9 Jun 2025 12:24:31 -0500
Subject: [PATCH] ci: gha: Remove ok-to-test label on every push
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This removes the ok-to-test label on every push, except if the PR author
has write access to the repo (ie. permission to modify labels).

This protects against attackers who would initially open a genuine PR,
then push malicious code after the initial review.

Signed-off-by: Aurélien Bombo <abombo@microsoft.com>
---
 .github/workflows/validate-ok-to-test.yml | 30 +++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 .github/workflows/validate-ok-to-test.yml

diff --git a/.github/workflows/validate-ok-to-test.yml b/.github/workflows/validate-ok-to-test.yml
new file mode 100644
index 000000000..33bfaeea6
--- /dev/null
+++ b/.github/workflows/validate-ok-to-test.yml
@@ -0,0 +1,30 @@
+name: Validate ok-to-test label
+
+on:
+  pull_request_target:
+    types: [synchronize]
+
+jobs:
+  remove-label-if-needed:
+    runs-on: ubuntu-22.04
+    permissions:
+      # SAFETY: Only enough to modify labels.
+      issues: write
+    steps:
+      - name: Remove ok-to-test label on push
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          AUTHOR: ${{ github.event.pull_request.user.login }}
+          OWNER: ${{ github.repository.owner.login }}
+          REPO: ${{ github.event.repository.name }}
+        run: |
+          permission="$(gh api "repos/${OWNER}/${REPO}/collaborators/${AUTHOR}/permission" --jq '.permission')"
+          echo "User ${AUTHOR} has permission '${permission}'"
+
+          if [[ "${permission}" != "write" && "${permission}" != "admin" ]]; then
+            echo "Removing 'ok-to-test' label"
+            gh pr edit "${PR_NUMBER}" --repo "${OWNER}/${REPO}" --remove-label "ok-to-test"
+          else
+            echo "User has label permission - skipping removal"
+          fi