Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d3e6b06a authored by Alex Buynytskyy's avatar Alex Buynytskyy Committed by Automerger Merge Worker
Browse files

Merge "Protect userlist.xml and <user>.xml from corruption." into udc-dev am: 5c45e708 

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22307542



Change-Id: I753ee8b62512cb030809f2c5623c56435bbca3a8
Signed-off-by: default avatarAutomerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
parents 77a657fa 5c45e708

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

+177 −117
Original line number Diff line number Diff line
@@ -278,6 +278,7 @@ public class UserManagerService extends IUserManager.Stub { 
    private static final long EPOCH_PLUS_30_YEARS = 30L * 365 * 24 * 60 * 60 * 1000L; // ms



    static final int WRITE_USER_MSG = 1;

    static final int WRITE_USER_LIST_MSG = 2;

    static final int WRITE_USER_DELAY = 2*1000;  // 2 seconds



    private static final long BOOT_USER_SET_TIMEOUT_MS = 300_000;
@@ -321,7 +322,6 @@ public class UserManagerService extends IUserManager.Stub { 
    private final Handler mHandler;



    private final File mUsersDir;

    @GuardedBy("mPackagesLock")

    private final File mUserListFile;



    private final IBinder mUserRestrictionToken = new Binder();
@@ -3623,17 +3623,33 @@ public class UserManagerService extends IUserManager.Stub { 
        mUpdatingSystemUserMode = true;

    }





    private ResilientAtomicFile getUserListFile() {

        File tempBackup = new File(mUserListFile.getParent(), mUserListFile.getName() + ".backup");

        File reserveCopy = new File(mUserListFile.getParent(),

                mUserListFile.getName() + ".reservecopy");

        int fileMode = FileUtils.S_IRWXU | FileUtils.S_IRWXG | FileUtils.S_IXOTH;

        return new ResilientAtomicFile(mUserListFile, tempBackup, reserveCopy, fileMode,

                "user list", (priority, msg) -> {

            Slog.e(LOG_TAG, msg);

            // Something went wrong, schedule full rewrite.

            scheduleWriteUserList();

        });

    }



    @GuardedBy({"mPackagesLock"})

    private void readUserListLP() {

        if (!mUserListFile.exists()) {

        try (ResilientAtomicFile file = getUserListFile()) {

            FileInputStream fin = null;

            try {

                fin = file.openRead();

                if (fin == null) {

                    Slog.e(LOG_TAG, "userlist.xml not found, fallback to single user");

                    fallbackToSingleUserLP();

                    return;

                }

        FileInputStream fis = null;

        AtomicFile userListFile = new AtomicFile(mUserListFile);

        try {

            fis = userListFile.openRead();

            final TypedXmlPullParser parser = Xml.resolvePullParser(fis);



                final TypedXmlPullParser parser = Xml.resolvePullParser(fin);

                int type;

                while ((type = parser.next()) != XmlPullParser.START_TAG

                        && type != XmlPullParser.END_DOCUMENT) {
@@ -3690,10 +3706,12 @@ public class UserManagerService extends IUserManager.Stub { 


                updateUserIds();

                upgradeIfNecessaryLP();

        } catch (IOException | XmlPullParserException e) {

            fallbackToSingleUserLP();

        } finally {

            IoUtils.closeQuietly(fis);

            } catch (Exception e) {

                // Remove corrupted file and retry.

                file.failRead(fin, e);

                readUserListLP();

                return;

            }

        }



        synchronized (mUsersLock) {
@@ -4099,6 +4117,18 @@ public class UserManagerService extends IUserManager.Stub { 
        }

    }



    private void scheduleWriteUserList() {

        if (DBG) {

            debug("scheduleWriteUserList");

        }

        // No need to wrap it within a lock -- worst case, we'll just post the same message

        // twice.

        if (!mHandler.hasMessages(WRITE_USER_LIST_MSG)) {

            Message msg = mHandler.obtainMessage(WRITE_USER_LIST_MSG);

            mHandler.sendMessageDelayed(msg, WRITE_USER_DELAY);

        }

    }



    private void scheduleWriteUser(UserData userData) {

        if (DBG) {

            debug("scheduleWriteUser");
@@ -4111,13 +4141,29 @@ public class UserManagerService extends IUserManager.Stub { 
        }

    }



    private ResilientAtomicFile getUserFile(int userId) {

        File file = new File(mUsersDir, userId + XML_SUFFIX);

        File tempBackup = new File(mUsersDir, userId + XML_SUFFIX + ".backup");

        File reserveCopy = new File(mUsersDir, userId + XML_SUFFIX + ".reservecopy");

        int fileMode = FileUtils.S_IRWXU | FileUtils.S_IRWXG | FileUtils.S_IXOTH;

        return new ResilientAtomicFile(file, tempBackup, reserveCopy, fileMode,

                "user info", (priority, msg) -> {

            Slog.e(LOG_TAG, msg);

            // Something went wrong, schedule full rewrite.

            UserData userData = getUserDataNoChecks(userId);

            if (userData != null) {

                scheduleWriteUser(userData);

            }

        });

    }



    @GuardedBy({"mPackagesLock"})

    private void writeUserLP(UserData userData) {

        if (DBG) {

            debug("writeUserLP " + userData);

        }

        try (ResilientAtomicFile userFile = getUserFile(userData.info.id)) {

            FileOutputStream fos = null;

        AtomicFile userFile = new AtomicFile(new File(mUsersDir, userData.info.id + XML_SUFFIX));

            try {

                fos = userFile.startWrite();

                writeUserLP(userData, fos);
@@ -4127,6 +4173,7 @@ public class UserManagerService extends IUserManager.Stub { 
                userFile.failWrite(fos);

            }

        }

    }



    /*

     * Writes the user file in this format:
@@ -4253,13 +4300,16 @@ public class UserManagerService extends IUserManager.Stub { 
        if (DBG) {

            debug("writeUserList");

        }



        try (ResilientAtomicFile file = getUserListFile()) {

            FileOutputStream fos = null;

        AtomicFile userListFile = new AtomicFile(mUserListFile);

            try {

            fos = userListFile.startWrite();

                fos = file.startWrite();



                final TypedXmlSerializer serializer = Xml.resolveSerializer(fos);

                serializer.startDocument(null, true);

            serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);

                serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output",

                        true);



                serializer.startTag(null, TAG_USERS);

                serializer.attributeInt(null, ATTR_NEXT_SERIAL_NO, mNextSerialNumber);
@@ -4289,29 +4339,32 @@ public class UserManagerService extends IUserManager.Stub { 
                serializer.endTag(null, TAG_USERS);



                serializer.endDocument();

            userListFile.finishWrite(fos);

                file.finishWrite(fos);

            } catch (Exception e) {

            userListFile.failWrite(fos);

            Slog.e(LOG_TAG, "Error writing user list");

                Slog.e(LOG_TAG, "Error writing user list", e);

                file.failWrite(fos);

            }

        }

    }



    @GuardedBy({"mPackagesLock"})

    private UserData readUserLP(int id) {

        try (ResilientAtomicFile file = getUserFile(id)) {

            FileInputStream fis = null;

            try {

            AtomicFile userFile =

                    new AtomicFile(new File(mUsersDir, Integer.toString(id) + XML_SUFFIX));

            fis = userFile.openRead();

                fis = file.openRead();

                if (fis == null) {

                    Slog.e(LOG_TAG, "User info not found, returning null, user id: " + id);

                    return null;

                }

                return readUserLP(id, fis);

        } catch (IOException ioe) {

            Slog.e(LOG_TAG, "Error reading user list");

        } catch (XmlPullParserException pe) {

            Slog.e(LOG_TAG, "Error reading user list");

        } finally {

            IoUtils.closeQuietly(fis);

            } catch (Exception e) {

                // Remove corrupted file and retry.

                Slog.e(LOG_TAG, "Error reading user info, user id: " + id);

                file.failRead(fis, e);

                return readUserLP(id);

            }

        }

        return null;

    }



    @GuardedBy({"mPackagesLock"})
@@ -5805,9 +5858,8 @@ public class UserManagerService extends IUserManager.Stub { 
        synchronized (mPackagesLock) {

            writeUserListLP();

        }

        // Remove user file

        AtomicFile userFile = new AtomicFile(new File(mUsersDir, userId + XML_SUFFIX));

        userFile.delete();

        // Remove user file(s)

        getUserFile(userId).delete();

        updateUserIds();

        if (RELEASE_DELETED_USER_ID) {

            synchronized (mUsersLock) {
@@ -6770,6 +6822,13 @@ public class UserManagerService extends IUserManager.Stub { 
        @Override

        public void handleMessage(Message msg) {

            switch (msg.what) {

                case WRITE_USER_LIST_MSG: {

                    removeMessages(WRITE_USER_LIST_MSG);

                    synchronized (mPackagesLock) {

                        writeUserListLP();

                    }

                    break;

                }

                case WRITE_USER_MSG:

                    removeMessages(WRITE_USER_MSG, msg.obj);

                    synchronized (mPackagesLock) {
@@ -6782,6 +6841,7 @@ public class UserManagerService extends IUserManager.Stub { 
                                    + ", it was probably removed before handler could handle it");

                        }

                    }

                    break;

            }

        }

    }