Merge "Validate package name passed to setApplicationRestrictions." into qt-dev am: 0b5ceb8cd2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19747771

Change-Id: Ie6bc78bc892b8ae40b1acb095cbb2a49ee3d0452
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

services/core/java/com/android/server/pm/UserManagerService.java

@@ -80,6 +80,7 @@ import android.security.GateKeeper;
 import android.service.gatekeeper.IGateKeeperService;
 import android.stats.devicepolicy.DevicePolicyEnums;
 import android.util.AtomicFile;
+import android.util.EventLog;
 import android.util.IntArray;
 import android.util.Log;
 import android.util.Slog;
@@ -3424,6 +3425,13 @@ public class UserManagerService extends IUserManager.Stub {
     public void setApplicationRestrictions(String packageName, Bundle restrictions,
             int userId) {
         checkSystemOrRoot("set application restrictions");
+        String validationResult = validateName(packageName);
+        if (validationResult != null) {
+            if (packageName.contains("../")) {
+                EventLog.writeEvent(0x534e4554, "239701237", -1, "");
+            }
+            throw new IllegalArgumentException("Invalid package name: " + validationResult);
+        }
         if (restrictions != null) {
             restrictions.setDefusable(true);
         }
@@ -3443,6 +3451,39 @@ public class UserManagerService extends IUserManager.Stub {
         mContext.sendBroadcastAsUser(changeIntent, UserHandle.of(userId));
     }
 
+    /**
+     * Check if the given name is valid.
+     *
+     * Note: the logic is taken from FrameworkParsingPackageUtils in master, edited to remove
+     * unnecessary parts. Copied here for a security fix.
+     *
+     * @param name The name to check.
+     * @return null if it's valid, error message if not
+     */
+    @VisibleForTesting
+    static String validateName(String name) {
+        final int n = name.length();
+        boolean front = true;
+        for (int i = 0; i < n; i++) {
+            final char c = name.charAt(i);
+            if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
+                front = false;
+                continue;
+            }
+            if (!front) {
+                if ((c >= '0' && c <= '9') || c == '_') {
+                    continue;
+                }
+                if (c == '.') {
+                    front = true;
+                    continue;
+                }
+            }
+            return "bad character '" + c + "'";
+        }
+        return null;
+    }
+
     private int getUidForPackage(String packageName) {
         long ident = Binder.clearCallingIdentity();
         try {

services/tests/servicestests/src/com/android/server/pm/UserManagerServiceTest.java

@@ -74,6 +74,13 @@ public class UserManagerServiceTest extends AndroidTestCase {
         assertEquals(accountName, um.getUserAccount(tempUserId));
     }
 
+    public void testValidateName() {
+        assertNull(UserManagerService.validateName("android"));
+        assertNull(UserManagerService.validateName("com.company.myapp"));
+        assertNotNull(UserManagerService.validateName("/../../data"));
+        assertNotNull(UserManagerService.validateName("/dir"));
+    }
+
     private Bundle createBundle() {
         Bundle result = new Bundle();
         // Tests for 6 allowed types: Integer, Boolean, String, String[], Bundle and Parcelable[]