Cap the size of app-defined permission trees (c55f9c04) · Commits · e / os / android_frameworks_base

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

+33 −1

Original line number	Diff line number	Diff line
		@@ -200,6 +200,9 @@ public class PackageManagerService extends IPackageManager.Stub {

		private static final boolean GET_CERTIFICATES = true;

		// Cap the size of permission trees that 3rd party apps can define
		private static final int MAX_PERMISSION_TREE_FOOTPRINT = 32768; // characters of text

		private static final int REMOVE_EVENTS =
		FileObserver.CLOSE_WRITE \| FileObserver.DELETE \| FileObserver.MOVED_FROM;
		private static final int ADD_EVENTS =
		@@ -2358,6 +2361,34 @@ public class PackageManagerService extends IPackageManager.Stub {
		return true;
		}

		int permissionInfoFootprint(PermissionInfo info) {
		int size = info.name.length();
		if (info.nonLocalizedLabel != null) size += info.nonLocalizedLabel.length();
		if (info.nonLocalizedDescription != null) size += info.nonLocalizedDescription.length();
		return size;
		}

		int calculateCurrentPermissionFootprintLocked(BasePermission tree) {
		int size = 0;
		for (BasePermission perm : mSettings.mPermissions.values()) {
		if (perm.uid == tree.uid) {
		size += perm.name.length() + permissionInfoFootprint(perm.perm.info);
		}
		}
		return size;
		}

		void enforcePermissionCapLocked(PermissionInfo info, BasePermission tree) {
		// We calculate the max size of permissions defined by this uid and throw
		// if that plus the size of 'info' would exceed our stated maximum.
		if (tree.uid != Process.SYSTEM_UID) {
		final int curTreeSize = calculateCurrentPermissionFootprintLocked(tree);
		if (curTreeSize + permissionInfoFootprint(info) > MAX_PERMISSION_TREE_FOOTPRINT) {
		throw new SecurityException("Permission tree size cap exceeded");
		}
		}
		}

		boolean addPermissionLocked(PermissionInfo info, boolean async) {
		if (info.labelRes == 0 && info.nonLocalizedLabel == null) {
		throw new SecurityException("Label must be specified in permission");
		@@ -2368,6 +2399,7 @@ public class PackageManagerService extends IPackageManager.Stub {
		boolean changed = true;
		int fixedLevel = PermissionInfo.fixProtectionLevel(info.protectionLevel);
		if (added) {
		enforcePermissionCapLocked(info, tree);
		bp = new BasePermission(info.name, tree.sourcePackage,
		BasePermission.TYPE_DYNAMIC);
		} else if (bp.type != BasePermission.TYPE_DYNAMIC) {