From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jing Ji <jji@google.com>
Date: Thu, 4 Aug 2022 11:36:26 -0700
Subject: [PATCH] DO NOT MERGE: Context#startInstrumentation could be started
 from SHELL only now.

Or, if an instrumentation starts another instrumentation and so on,
and the original instrumentation is started from SHELL, allow all
Context#startInstrumentation calls in this chain.

Otherwise, it'll throw a SecurityException.

Bug: 237766679
Test: atest CtsAppTestCases:InstrumentationTest
Merged-In: Ia08f225c21a3933067d066a578ea4af9c23e7d4c
Merged-In: I1b76f61c5fd6c9f7e738978592260945a606f40c
Merged-In: I3ea7aa27bd776fec546908a37f667f680da9c892
Change-Id: I7ca7345b064e8e74f7037b8fa3ed45bb6423e406
(cherry picked from commit 8c90891a38ecb5047e115e13baf700a8b486a5d1)
Merged-In: I7ca7345b064e8e74f7037b8fa3ed45bb6423e406
---
 .../server/am/ActivityManagerService.java     | 34 +++++++++++++++++++
 .../com/android/server/am/ProcessRecord.java  |  4 +++
 2 files changed, 38 insertions(+)

diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index e6f400c31bde..3feb040b9f47 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -4331,6 +4331,26 @@ public class ActivityManagerService extends IActivityManager.Stub
         return procState;
     }
 
+    @GuardedBy("this")
+    private boolean hasActiveInstrumentationLocked(int pid) {
+        if (pid == 0) {
+            return false;
+        }
+        synchronized (mPidsSelfLocked) {
+            ProcessRecord process = mPidsSelfLocked.get(pid);
+            return process != null && process.getActiveInstrumentation() != null;
+        }
+    }
+    private String getPackageNameByPid(int pid) {
+        synchronized (mPidsSelfLocked) {
+            final ProcessRecord app = mPidsSelfLocked.get(pid);
+            if (app != null && app.info != null) {
+                return app.info.packageName;
+            }
+            return null;
+        }
+    }
+
     private boolean isCallerShell() {
         final int callingUid = Binder.getCallingUid();
         return callingUid == SHELL_UID || callingUid == ROOT_UID;
@@ -20059,6 +20079,8 @@ public class ActivityManagerService extends IActivityManager.Stub
             IInstrumentationWatcher watcher, IUiAutomationConnection uiAutomationConnection,
             int userId, String abiOverride) {
         enforceNotIsolatedCaller("startInstrumentation");
+        final int callingUid = Binder.getCallingUid();
+        final int callingPid = Binder.getCallingPid();
         userId = mUserController.handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(),
                 userId, false, ALLOW_FULL_ONLY, "startInstrumentation", null);
         // Refuse possible leaked file descriptors
@@ -20107,6 +20129,18 @@ public class ActivityManagerService extends IActivityManager.Stub
                 throw new SecurityException(msg);
             }
 
+            if (!Build.IS_DEBUGGABLE && callingUid != ROOT_UID && callingUid != SHELL_UID
+                    && callingUid != SYSTEM_UID && !hasActiveInstrumentationLocked(callingPid)) {
+                // If it's not debug build and not called from root/shell/system uid, reject it.
+                final String msg = "Permission Denial: instrumentation test "
+                        + className + " from pid=" + callingPid + ", uid=" + callingUid
+                        + ", pkgName=" + getPackageNameByPid(callingPid)
+                        + " not allowed because it's not started from SHELL";
+                Slog.wtfQuiet(TAG, msg);
+                reportStartInstrumentationFailureLocked(watcher, className, msg);
+                throw new SecurityException(msg);
+            }
+
             ActiveInstrumentation activeInstr = new ActiveInstrumentation(this);
             activeInstr.mClass = className;
             String defProcess = ai.processName;;
diff --git a/services/core/java/com/android/server/am/ProcessRecord.java b/services/core/java/com/android/server/am/ProcessRecord.java
index 7e037eea285c..14edfe89ad0f 100644
--- a/services/core/java/com/android/server/am/ProcessRecord.java
+++ b/services/core/java/com/android/server/am/ProcessRecord.java
@@ -771,4 +771,8 @@ final class ProcessRecord {
         }
         return list;
     }
+
+    ActiveInstrumentation getActiveInstrumentation() {
+        return instr;
+    }
 }