DivestOS/Patches/LineageOS-15.1/android_frameworks_base/364033-backport.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Pavel Grafov <pgrafov@google.com>
Date: Wed, 5 Apr 2023 15:15:41 +0000
Subject: [PATCH] Ensure policy has no absurdly long strings
The following APIs now enforce limits and throw IllegalArgumentException
when limits are violated:
* DPM.setTrustAgentConfiguration() limits agent packgage name,
component name, and strings within configuration bundle.
* DPM.setPermittedAccessibilityServices() limits package names.
* DPM.setPermittedInputMethods() limits package names.
* DPM.setAccountManagementDisabled() limits account name.
* DPM.setLockTaskPackages() limits package names.
* DPM.setAffiliationIds() limits id.
* DPM.transferOwnership() limits strings inside the bundle.
Package names are limited at 223, because they become directory names
and it is a filesystem restriction, see FrameworkParsingPackageUtils.
All other strings are limited at 65535, because longer ones break binary
XML serializer.
The following APIs silently truncate strings that are long beyond reason:
* DPM.setShortSupportMessage() truncates message at 200.
* DPM.setLongSupportMessage() truncates message at 20000.
* DPM.setOrganizationName() truncates org name at 200.
Bug: 260729089
Test: atest com.android.server.devicepolicy
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:bb7e82ceaa6d16267e7b0e14563161b506d26be8)
Merged-In: Idcf54e408722f164d16bf2f24a00cd1f5b626d23
Change-Id: Idcf54e408722f164d16bf2f24a00cd1f5b626d23
---
.../app/admin/DevicePolicyManager.java | 3 +-
.../DevicePolicyManagerService.java | 89 ++++++++++++++++++-
2 files changed, 88 insertions(+), 4 deletions(-)
diff --git a/core/java/android/app/admin/DevicePolicyManager.java b/core/java/android/app/admin/DevicePolicyManager.java
index 0c43e23b13c5..7d9e1a1d9144 100644
--- a/core/java/android/app/admin/DevicePolicyManager.java
+++ b/core/java/android/app/admin/DevicePolicyManager.java
@@ -7157,7 +7157,8 @@ public class DevicePolicyManager {
/**
* Called by a device admin to set the long support message. This will be displayed to the user
- * in the device administators settings screen.
+ * in the device administrators settings screen. If the message is longer than 20000 characters
+ * it may be truncated.
* <p>
* If the long support message needs to be localized, it is the responsibility of the
* {@link DeviceAdminReceiver} to listen to the {@link Intent#ACTION_LOCALE_CHANGED} broadcast
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index 9410f100ec37..ab52e320b52c 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -199,6 +199,7 @@ import java.io.IOException;
import java.io.PrintWriter;
import java.nio.charset.StandardCharsets;
import java.text.DateFormat;
+import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
@@ -206,6 +207,7 @@ import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Map.Entry;
+import java.util.Queue;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
@@ -262,6 +264,15 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
private static final int REQUEST_EXPIRE_PASSWORD = 5571;
+ // Binary XML serializer doesn't support longer strings
+ private static final int MAX_POLICY_STRING_LENGTH = 65535;
+ // FrameworkParsingPackageUtils#MAX_FILE_NAME_SIZE, Android packages are used in dir names.
+ private static final int MAX_PACKAGE_NAME_LENGTH = 223;
+
+ private static final int MAX_LONG_SUPPORT_MESSAGE_LENGTH = 20000;
+ private static final int MAX_SHORT_SUPPORT_MESSAGE_LENGTH = 200;
+ private static final int MAX_ORG_NAME_LENGTH = 200;
+
private static final long MS_PER_DAY = TimeUnit.DAYS.toMillis(1);
private static final long EXPIRATION_GRACE_PERIOD_MS = 5 * MS_PER_DAY; // 5 days, in ms
@@ -7575,6 +7586,12 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
}
Preconditions.checkNotNull(admin, "admin is null");
Preconditions.checkNotNull(agent, "agent is null");
+ enforceMaxPackageNameLength(agent.getPackageName());
+ final String agentAsString = agent.flattenToString();
+ enforceMaxStringLength(agentAsString, "agent name");
+ if (args != null) {
+ enforceMaxStringLength(args, "args");
+ }
final int userHandle = UserHandle.getCallingUserId();
synchronized (this) {
ActiveAdmin ap = getActiveAdminForCallerLocked(admin,
@@ -7777,6 +7794,10 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
Preconditions.checkNotNull(who, "ComponentName is null");
if (packageList != null) {
+ for (String pkg : (List<String>) packageList) {
+ enforceMaxPackageNameLength(pkg);
+ }
+
int userId = UserHandle.getCallingUserId();
List<AccessibilityServiceInfo> enabledServices = null;
long id = mInjector.binderClearCallingIdentity();
@@ -7959,6 +7980,10 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
final int callingUserId = mInjector.userHandleGetCallingUserId();
if (packageList != null) {
+ for (String pkg : (List<String>) packageList) {
+ enforceMaxPackageNameLength(pkg);
+ }
+
// InputMethodManager fetches input methods for current user.
// So this can only be set when calling user is the current user
// or parent is current user in case of managed profiles.
@@ -8623,6 +8648,7 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
return;
}
Preconditions.checkNotNull(who, "ComponentName is null");
+ enforceMaxStringLength(accountType, "account type");
synchronized (this) {
ActiveAdmin ap = getActiveAdminForCallerLocked(who,
DeviceAdminInfo.USES_POLICY_PROFILE_OWNER);
@@ -8886,6 +8912,9 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
throws SecurityException {
Preconditions.checkNotNull(who, "ComponentName is null");
Preconditions.checkNotNull(packages, "packages is null");
+ for (String pkg : packages) {
+ enforceMaxPackageNameLength(pkg);
+ }
synchronized (this) {
getActiveAdminForCallerLocked(who, DeviceAdminInfo.USES_POLICY_PROFILE_OWNER);
@@ -10001,6 +10030,8 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
return;
}
Preconditions.checkNotNull(who, "ComponentName is null");
+ message = truncateIfLonger(message, MAX_SHORT_SUPPORT_MESSAGE_LENGTH);
+
final int userHandle = mInjector.userHandleGetCallingUserId();
synchronized (this) {
ActiveAdmin admin = getActiveAdminForUidLocked(who,
@@ -10030,6 +10061,9 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
if (!mHasFeature) {
return;
}
+
+ message = truncateIfLonger(message, MAX_LONG_SUPPORT_MESSAGE_LENGTH);
+
Preconditions.checkNotNull(who, "ComponentName is null");
final int userHandle = mInjector.userHandleGetCallingUserId();
synchronized (this) {
@@ -10048,6 +10082,7 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
return null;
}
Preconditions.checkNotNull(who, "ComponentName is null");
+
synchronized (this) {
ActiveAdmin admin = getActiveAdminForUidLocked(who,
mInjector.binderGetCallingUid());
@@ -10159,6 +10194,8 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
Preconditions.checkNotNull(who, "ComponentName is null");
final int userHandle = mInjector.userHandleGetCallingUserId();
+ text = truncateIfLonger(text, MAX_ORG_NAME_LENGTH);
+
synchronized (this) {
ActiveAdmin admin = getActiveAdminForCallerLocked(who,
DeviceAdminInfo.USES_POLICY_PROFILE_OWNER);
@@ -10220,9 +10257,8 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
throw new IllegalArgumentException("ids must not be null");
}
for (String id : ids) {
- if (TextUtils.isEmpty(id)) {
- throw new IllegalArgumentException("ids must not contain empty string");
- }
+ Preconditions.checkArgument(!TextUtils.isEmpty(id), "ids must not have empty string");
+ enforceMaxStringLength(id, "affiliation id");
}
final Set<String> affiliationIds = new ArraySet<>(ids);
@@ -11198,4 +11234,51 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
new ArrayList<>(getUserData(userId).mOwnerInstalledCaCerts));
}
}
+
+ /**
+ * Truncates char sequence to maximum length, nulls are ignored.
+ */
+ private static CharSequence truncateIfLonger(CharSequence input, int maxLength) {
+ return input == null || input.length() <= maxLength
+ ? input
+ : input.subSequence(0, maxLength);
+ }
+
+ /**
+ * Throw if string argument is too long to be serialized.
+ */
+ private static void enforceMaxStringLength(String str, String argName) {
+ Preconditions.checkArgument(
+ str.length() <= MAX_POLICY_STRING_LENGTH, argName + " loo long");
+ }
+
+ private static void enforceMaxPackageNameLength(String pkg) {
+ Preconditions.checkArgument(
+ pkg.length() <= MAX_PACKAGE_NAME_LENGTH, "Package name too long");
+ }
+
+ /**
+ * Throw if persistable bundle contains any string that we can't serialize.
+ */
+ private static void enforceMaxStringLength(PersistableBundle bundle, String argName) {
+ // Persistable bundles can have other persistable bundles as values, traverse with a queue.
+ Queue<PersistableBundle> queue = new ArrayDeque<>();
+ queue.add(bundle);
+ while (!queue.isEmpty()) {
+ PersistableBundle current = queue.remove();
+ for (String key : current.keySet()) {
+ enforceMaxStringLength(key, "key in " + argName);
+ Object value = current.get(key);
+ if (value instanceof String) {
+ enforceMaxStringLength((String) value, "string value in " + argName);
+ } else if (value instanceof String[]) {
+ for (String str : (String[]) value) {
+ enforceMaxStringLength(str, "string value in " + argName);
+ }
+ } else if (value instanceof PersistableBundle) {
+ queue.add((PersistableBundle) value);
+ }
+ }
+ }
+ }
}