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Commit dadd7c98 authored by Pavel Grafov's avatar Pavel Grafov Committed by Android Build Coastguard Worker
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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:456dbcae5ae4bc0d8f73f8cb97b57c8de6958f9c)
Merged-In: Idcf54e408722f164d16bf2f24a00cd1f5b626d23
Change-Id: Idcf54e408722f164d16bf2f24a00cd1f5b626d23
parent 132c85c4

core/java/android/app/admin/DevicePolicyManager.java

+2 −1
Original line number Diff line number Diff line
@@ -12402,7 +12402,8 @@ 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

























services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java



+89
−3




























Original line number
Diff line number
Diff line








@@ -397,6 +397,7 @@ import java.security.cert.CertificateFactory;













import java.security.cert.X509Certificate;















import java.text.DateFormat;















import java.time.LocalDate;













import java.util.ArrayDeque;















import java.util.ArrayList;















import java.util.Arrays;















import java.util.Collection;









@@ -408,6 +409,7 @@ import java.util.List;













import java.util.Locale;















import java.util.Map;















import java.util.Objects;













import java.util.Queue;















import java.util.Set;















import java.util.concurrent.Executor;















import java.util.concurrent.TimeUnit;










@@ -439,7 +441,15 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {



























    private static final int REQUEST_PROFILE_OFF_DEADLINE = 5572;



























    // 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_PROFILE_NAME_LENGTH = 200;













    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);
























@@ -10053,6 +10063,12 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













        }















        Objects.requireNonNull(admin, "admin is null");















        Objects.requireNonNull(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 (getLockObject()) {















            ActiveAdmin ap = getActiveAdminForCallerLocked(admin,










@@ -10294,6 +10310,10 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













        final CallerIdentity caller = getCallerIdentity(who);





























        if (packageList != null) {













            for (String pkg : packageList) {













                enforceMaxPackageNameLength(pkg);













            }



























            int userId = caller.getUserId();















            final List<AccessibilityServiceInfo> enabledServices;















            long id = mInjector.binderClearCallingIdentity();










@@ -10463,6 +10483,10 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













        }





























        if (packageList != null) {













            for (String pkg : packageList) {













                enforceMaxPackageNameLength(pkg);













            }



























            List<InputMethodInfo> enabledImes = mInjector.binderWithCleanCallingIdentity(() ->















                    InputMethodManagerInternal.get().getEnabledInputMethodListAsUser(userId));















            if (enabledImes != null) {










@@ -11793,6 +11817,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













            return;















        }















        Objects.requireNonNull(who, "ComponentName is null");













        enforceMaxStringLength(accountType, "account type");



























        final CallerIdentity caller = getCallerIdentity(who);















        synchronized (getLockObject()) {















            /*










@@ -12214,6 +12240,10 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













            throws SecurityException {















        Objects.requireNonNull(who, "ComponentName is null");















        Objects.requireNonNull(packages, "packages is null");













        for (String pkg : packages) {













            enforceMaxPackageNameLength(pkg);













        }



























        final CallerIdentity caller = getCallerIdentity(who);





























        synchronized (getLockObject()) {










@@ -14333,6 +14363,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













            return;















        }















        Objects.requireNonNull(who, "ComponentName is null");













        message = truncateIfLonger(message, MAX_SHORT_SUPPORT_MESSAGE_LENGTH);



























        final CallerIdentity caller = getCallerIdentity(who);















        synchronized (getLockObject()) {















            ActiveAdmin admin = getActiveAdminForUidLocked(who, caller.getUid());










@@ -14365,6 +14397,9 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













        if (!mHasFeature) {















            return;















        }

























        message = truncateIfLonger(message, MAX_LONG_SUPPORT_MESSAGE_LENGTH);



























        Objects.requireNonNull(who, "ComponentName is null");















        final CallerIdentity caller = getCallerIdentity(who);















        synchronized (getLockObject()) {










@@ -14514,6 +14549,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













        Objects.requireNonNull(who, "ComponentName is null");















        final CallerIdentity caller = getCallerIdentity(who);



























        text = truncateIfLonger(text, MAX_ORG_NAME_LENGTH);



























        synchronized (getLockObject()) {















            ActiveAdmin admin = getProfileOwnerOrDeviceOwnerLocked(caller);















            if (!TextUtils.equals(admin.organizationName, text)) {










@@ -14786,9 +14823,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













            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);










@@ -16099,6 +16135,9 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













                "Provided administrator and target are the same object.");















        Preconditions.checkArgument(!admin.getPackageName().equals(target.getPackageName()),















                "Provided administrator and target have the same package name.");













        if (bundle != null) {













            enforceMaxStringLength(bundle, "bundle");













        }





























        final CallerIdentity caller = getCallerIdentity(admin);















        Preconditions.checkCallAuthorization(










@@ -18900,4 +18939,51 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {













            return result;















        });















    }

























    /**













     * 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);













                }













            }













        }













    }















}