Fix security vulnerability that creates user with no restrictions when accountOptions are too long. (33a90988) · Commits · e / os / android_frameworks_base

core/java/android/os/PersistableBundle.java

+37 −0

Original line number	Diff line number	Diff line
		@@ -294,6 +294,43 @@ public final class PersistableBundle extends BaseBundle implements Cloneable, Pa
		XmlUtils.writeMapXml(mMap, out, this);
		}

		/**
		* Checks whether all keys and values are within the given character limit.
		* Note: Maximum character limit of String that can be saved to XML as part of bundle is 65535.
		* Otherwise IOException is thrown.
		* @param limit length of String keys and values in the PersistableBundle, including nested
		* PersistableBundles to check against.
		*
		* @hide
		*/
		public boolean isBundleContentsWithinLengthLimit(int limit) {
		unparcel();
		if (mMap == null) {
		return true;
		}
		for (int i = 0; i < mMap.size(); i++) {
		if (mMap.keyAt(i) != null && mMap.keyAt(i).length() > limit) {
		return false;
		}
		final Object value = mMap.valueAt(i);
		if (value instanceof String && ((String) value).length() > limit) {
		return false;
		} else if (value instanceof String[]) {
		String[] stringArray = (String[]) value;
		for (int j = 0; j < stringArray.length; j++) {
		if (stringArray[j] != null
		&& stringArray[j].length() > limit) {
		return false;
		}
		}
		} else if (value instanceof PersistableBundle
		&& !((PersistableBundle) value).isBundleContentsWithinLengthLimit(limit)) {
		return false;
		}
		}
		return true;
		}

		/** @hide */
		static class MyReadMapCallback implements XmlUtils.ReadMapCallback {
		@Override

core/java/android/os/UserManager.java

+19 −4

Original line number	Diff line number	Diff line
		@@ -103,6 +103,21 @@ public class UserManager {
		/** Whether the device is in headless system user mode; null until cached. */
		private static Boolean sIsHeadlessSystemUser = null;

		/** Maximum length of username.
		* @hide
		*/
		public static final int MAX_USER_NAME_LENGTH = 100;

		/** Maximum length of user property String value.
		* @hide
		*/
		public static final int MAX_ACCOUNT_STRING_LENGTH = 500;

		/** Maximum length of account options String values.
		* @hide
		*/
		public static final int MAX_ACCOUNT_OPTIONS_LENGTH = 1000;

		/**
		* User type representing a {@link UserHandle#USER_SYSTEM system} user that is a human user.
		* This type of user cannot be created; it can only pre-exist on first boot.
		@@ -4204,15 +4219,15 @@ public class UserManager {
		* This API should only be called if the current user is an {@link #isAdminUser() admin} user,
		* as otherwise the returned intent will not be able to create a user.
		*
		* @param userName Optional name to assign to the user.
		* @param userName Optional name to assign to the user. Character limit is 100.
		* @param accountName Optional account name that will be used by the setup wizard to initialize
		* the user.
		* the user. Character limit is 500.
		* @param accountType Optional account type for the account to be created. This is required
		* if the account name is specified.
		* if the account name is specified. Character limit is 500.
		* @param accountOptions Optional bundle of data to be passed in during account creation in the
		* new user via {@link AccountManager#addAccount(String, String, String[],
		* Bundle, android.app.Activity, android.accounts.AccountManagerCallback,
		* Handler)}.
		* Handler)}. Character limit is 1000.
		* @return An Intent that can be launched from an Activity.
		* @see #USER_CREATION_FAILED_NOT_PERMITTED
		* @see #USER_CREATION_FAILED_NO_MORE_USERS

core/java/com/android/internal/app/ConfirmUserCreationActivity.java

+12 −0

Original line number	Diff line number	Diff line
		@@ -116,6 +116,14 @@ public class ConfirmUserCreationActivity extends AlertActivity
		if (cantCreateUser) {
		setResult(UserManager.USER_CREATION_FAILED_NOT_PERMITTED);
		return null;
		} else if (!(isUserPropertyWithinLimit(mUserName, UserManager.MAX_USER_NAME_LENGTH)
		&& isUserPropertyWithinLimit(mAccountName, UserManager.MAX_ACCOUNT_STRING_LENGTH)
		&& isUserPropertyWithinLimit(mAccountType, UserManager.MAX_ACCOUNT_STRING_LENGTH))
		\|\| (mAccountOptions != null && !mAccountOptions.isBundleContentsWithinLengthLimit(
		UserManager.MAX_ACCOUNT_OPTIONS_LENGTH))) {
		setResult(UserManager.USER_CREATION_FAILED_NOT_PERMITTED);
		Log.i(TAG, "User properties must not exceed their character limits");
		return null;
		} else if (cantCreateAnyMoreUsers) {
		setResult(UserManager.USER_CREATION_FAILED_NO_MORE_USERS);
		return null;
		@@ -144,4 +152,8 @@ public class ConfirmUserCreationActivity extends AlertActivity
		}
		finish();
		}

		private boolean isUserPropertyWithinLimit(String property, int limit) {
		return property == null \|\| property.length() <= limit;
		}
		}

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

+17 −13

Original line number	Diff line number	Diff line
		@@ -284,8 +284,6 @@ public class UserManagerService extends IUserManager.Stub {

		private static final int USER_VERSION = 11;

		private static final int MAX_USER_STRING_LENGTH = 500;

		private static final long EPOCH_PLUS_30_YEARS = 30L * 365 * 24 * 60 * 60 * 1000L; // ms

		static final int WRITE_USER_MSG = 1;
		@@ -4261,16 +4259,18 @@ public class UserManagerService extends IUserManager.Stub {
		if (userData.persistSeedData) {
		if (userData.seedAccountName != null) {
		serializer.attribute(null, ATTR_SEED_ACCOUNT_NAME,
		truncateString(userData.seedAccountName));
		truncateString(userData.seedAccountName,
		UserManager.MAX_ACCOUNT_STRING_LENGTH));
		}
		if (userData.seedAccountType != null) {
		serializer.attribute(null, ATTR_SEED_ACCOUNT_TYPE,
		truncateString(userData.seedAccountType));
		truncateString(userData.seedAccountType,
		UserManager.MAX_ACCOUNT_STRING_LENGTH));
		}
		}
		if (userInfo.name != null) {
		serializer.startTag(null, TAG_NAME);
		serializer.text(truncateString(userInfo.name));
		serializer.text(truncateString(userInfo.name, UserManager.MAX_USER_NAME_LENGTH));
		serializer.endTag(null, TAG_NAME);
		}
		synchronized (mRestrictionsLock) {
		@@ -4319,11 +4319,11 @@ public class UserManagerService extends IUserManager.Stub {
		serializer.endDocument();
		}

		private String truncateString(String original) {
		if (original == null \|\| original.length() <= MAX_USER_STRING_LENGTH) {
		private String truncateString(String original, int limit) {
		if (original == null \|\| original.length() <= limit) {
		return original;
		}
		return original.substring(0, MAX_USER_STRING_LENGTH);
		return original.substring(0, limit);
		}

		/*
		@@ -4771,8 +4771,7 @@ public class UserManagerService extends IUserManager.Stub {
		@UserIdInt int parentId, boolean preCreate, @Nullable String[] disallowedPackages,
		@NonNull TimingsTraceAndSlog t, @Nullable Object token)
		throws UserManager.CheckedUserOperationException {

		String truncatedName = truncateString(name);
		String truncatedName = truncateString(name, UserManager.MAX_USER_NAME_LENGTH);
		final UserTypeDetails userTypeDetails = mUserTypes.get(userType);
		if (userTypeDetails == null) {
		throwCheckedUserOperationException(
		@@ -6373,9 +6372,14 @@ public class UserManagerService extends IUserManager.Stub {
		Slog.e(LOG_TAG, "No such user for settings seed data u=" + userId);
		return;
		}
		userData.seedAccountName = truncateString(accountName);
		userData.seedAccountType = truncateString(accountType);
		userData.seedAccountName = truncateString(accountName,
		UserManager.MAX_ACCOUNT_STRING_LENGTH);
		userData.seedAccountType = truncateString(accountType,
		UserManager.MAX_ACCOUNT_STRING_LENGTH);
		if (accountOptions != null && accountOptions.isBundleContentsWithinLengthLimit(
		UserManager.MAX_ACCOUNT_OPTIONS_LENGTH)) {
		userData.seedAccountOptions = accountOptions;
		}
		userData.persistSeedData = persist;
		}
		if (persist) {

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

+1 −1

Original line number	Diff line number	Diff line
		@@ -331,7 +331,7 @@ public final class UserManagerServiceTest {
		@Test
		public void testCreateUserWithLongName_TruncatesName() {
		UserInfo user = mUms.createUserWithThrow(generateLongString(), USER_TYPE_FULL_SECONDARY, 0);
		assertThat(user.name.length()).isEqualTo(500);
		assertThat(user.name.length()).isEqualTo(UserManager.MAX_USER_NAME_LENGTH);
		UserInfo user1 = mUms.createUserWithThrow("Test", USER_TYPE_FULL_SECONDARY, 0);
		assertThat(user1.name.length()).isEqualTo(4);
		}