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Commit 655f1a45 authored by Dmitrii Merkurev's avatar Dmitrii Merkurev
Browse files

Currently, Uri Permissions read/write grants are modified/accessed from... 

Currently, Uri Permissions read/write grants  are modified/accessed from different parts across the system:

* `UriGrantsManagerService.revokeUriPermissionFromOwner` (which is using `owner.removeUriPermission` (iterating over all read/write permissions for owner) without locking)

* `UriGrantsManagerService.grantUriPermissionUnchecked` (which is using `UriPermission.grantModes` (adding new read/write permissions for owner) without any locking)

* `UriGrantsManagerService.removeUriPermissionsForPackageLocked` and `UriGrantsManagerService.revokeUriPermissionLocked` (which is using `UriPermission.revokeModes` (removing read/write permissions for owner) with main UriGrantsManagerService lock)

* `WindowManager` and `ActivityManager` (that using `removeUriPermissions` directly (iterating over all read/write permissions for owner) without any locking)

Introduce synchronization for this part of the system.

Bug: 213993781
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/uri/
Change-Id: Idbe02e53e2b4c9fcb02d6e22dc92480d711c7779
parent 71f72f13

services/core/java/com/android/server/uri/UriPermissionOwner.java

+82 −58
Original line number Diff line number Diff line
@@ -30,7 +30,9 @@ import com.android.server.am.UriPermissionOwnerProto; 
import com.google.android.collect.Sets;



import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;



public class UriPermissionOwner {

    private final UriGrantsManagerInternal mService;
@@ -79,10 +81,13 @@ public class UriPermissionOwner { 
    }



    void removeUriPermission(GrantUri grantUri, int mode, String targetPgk, int targetUserId) {

        final List<UriPermission> permissionsToRemove = new ArrayList<>();



        synchronized (this) {

            if ((mode & FLAG_GRANT_READ_URI_PERMISSION) != 0 && mReadPerms != null) {

            Iterator<UriPermission> it = mReadPerms.iterator();

                final Iterator<UriPermission> it = mReadPerms.iterator();

                while (it.hasNext()) {

                UriPermission perm = it.next();

                    final UriPermission perm = it.next();

                    if (grantUri != null && !grantUri.equals(perm.uri)) {

                        continue;

                    }
@@ -92,18 +97,19 @@ public class UriPermissionOwner { 
                    if (targetUserId != UserHandle.USER_ALL && targetUserId != perm.targetUserId) {

                        continue;

                    }

                    permissionsToRemove.add(perm);

                    perm.removeReadOwner(this);

                mService.removeUriPermissionIfNeeded(perm);

                    it.remove();

                }

                if (mReadPerms.isEmpty()) {

                    mReadPerms = null;

                }

            }



            if ((mode & FLAG_GRANT_WRITE_URI_PERMISSION) != 0 && mWritePerms != null) {

            Iterator<UriPermission> it = mWritePerms.iterator();

                final Iterator<UriPermission> it = mWritePerms.iterator();

                while (it.hasNext()) {

                UriPermission perm = it.next();

                    final UriPermission perm = it.next();

                    if (grantUri != null && !grantUri.equals(perm.uri)) {

                        continue;

                    }
@@ -113,8 +119,8 @@ public class UriPermissionOwner { 
                    if (targetUserId != UserHandle.USER_ALL && targetUserId != perm.targetUserId) {

                        continue;

                    }

                    permissionsToRemove.add(perm);

                    perm.removeWriteOwner(this);

                mService.removeUriPermissionIfNeeded(perm);

                    it.remove();

                }

                if (mWritePerms.isEmpty()) {
@@ -123,55 +129,73 @@ public class UriPermissionOwner { 
            }

        }



        final int permissionsToRemoveSize = permissionsToRemove.size();

        for (int i = 0; i < permissionsToRemoveSize; i++) {

            mService.removeUriPermissionIfNeeded(permissionsToRemove.get(i));

        }

    }



    public void addReadPermission(UriPermission perm) {

        synchronized (this) {

            if (mReadPerms == null) {

                mReadPerms = Sets.newArraySet();

            }

            mReadPerms.add(perm);

        }

    }



    public void addWritePermission(UriPermission perm) {

        synchronized (this) {

            if (mWritePerms == null) {

                mWritePerms = Sets.newArraySet();

            }

            mWritePerms.add(perm);

        }

    }



    public void removeReadPermission(UriPermission perm) {

        synchronized (this) {

            mReadPerms.remove(perm);

            if (mReadPerms.isEmpty()) {

                mReadPerms = null;

            }

        }

    }



    public void removeWritePermission(UriPermission perm) {

        synchronized (this) {

            mWritePerms.remove(perm);

            if (mWritePerms.isEmpty()) {

                mWritePerms = null;

            }

        }

    }



    public void dump(PrintWriter pw, String prefix) {

        synchronized (this) {

            if (mReadPerms != null) {

            pw.print(prefix); pw.print("readUriPermissions="); pw.println(mReadPerms);

                pw.print(prefix);

                pw.print("readUriPermissions=");

                pw.println(mReadPerms);

            }

            if (mWritePerms != null) {

            pw.print(prefix); pw.print("writeUriPermissions="); pw.println(mWritePerms);

                pw.print(prefix);

                pw.print("writeUriPermissions=");

                pw.println(mWritePerms);

            }

        }

    }



    public void dumpDebug(ProtoOutputStream proto, long fieldId) {

        long token = proto.start(fieldId);

        proto.write(UriPermissionOwnerProto.OWNER, mOwner.toString());

        synchronized (this) {

            if (mReadPerms != null) {

            synchronized (mReadPerms) {

                for (UriPermission p : mReadPerms) {

                    p.uri.dumpDebug(proto, UriPermissionOwnerProto.READ_PERMS);

                }

            }

        }

            if (mWritePerms != null) {

            synchronized (mWritePerms) {

                for (UriPermission p : mWritePerms) {

                    p.uri.dumpDebug(proto, UriPermissionOwnerProto.WRITE_PERMS);

                }