From f279a5bc0dd54aadd97a0941d5fed4584794ba57 Mon Sep 17 00:00:00 2001 From: Jeff Sharkey Date: Wed, 30 Nov 2016 16:07:00 -0700 Subject: [PATCH] DO NOT MERGE. Retain DownloadManager Uri grants when clearing. As part of fixing a recent security issue, DownloadManager now needs to issue Uri permission grants for all downloads. However, if an app that requested a download is upgraded or otherwise force-stopped, the required permission grants are removed. We could tell DownloadManager about the app being stopped, but that would be racy (due to background broadcast), and waking it up would degrade system health. Instead, as a special case we now only consider clearing DownloadManager permission grants when app data is being cleared. Bug: 32172542, 30537115 Test: builds, boots, app upgrade doesn't clear grants Change-Id: I7e3d4546fd12bfe5f81b9fb9857ece58d574a6b9 (cherry picked from commit 23ec811266fb728cf159a90ce4882b3c9bac1887) --- core/java/android/provider/Downloads.java | 2 ++ .../java/com/android/server/am/ActivityManagerService.java | 7 +++++++ 2 files changed, 9 insertions(+) diff --git a/core/java/android/provider/Downloads.java b/core/java/android/provider/Downloads.java index b2d9b934d79b0..dc874bb32372a 100644 --- a/core/java/android/provider/Downloads.java +++ b/core/java/android/provider/Downloads.java @@ -41,6 +41,8 @@ public final class Downloads { public static final class Impl implements BaseColumns { private Impl() {} + public static final String AUTHORITY = "downloads"; + /** * The permission to access the download manager */ diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java index 14e75eb5493a2..ed1fefbff96be 100755 --- a/services/core/java/com/android/server/am/ActivityManagerService.java +++ b/services/core/java/com/android/server/am/ActivityManagerService.java @@ -184,6 +184,7 @@ import android.os.SystemProperties; import android.os.UpdateLock; import android.os.UserHandle; import android.os.UserManager; +import android.provider.Downloads; import android.provider.Settings; import android.text.format.DateUtils; import android.text.format.Time; @@ -7756,6 +7757,12 @@ public final class ActivityManagerService extends ActivityManagerNative // Only inspect grants matching package if (packageName == null || perm.sourcePkg.equals(packageName) || perm.targetPkg.equals(packageName)) { + // Hacky solution as part of fixing a security bug; ignore + // grants associated with DownloadManager so we don't have + // to immediately launch it to regrant the permissions + if (Downloads.Impl.AUTHORITY.equals(perm.uri.uri.getAuthority()) + && !persistable) continue; + persistChanged |= perm.revokeModes(persistable ? ~0 : ~Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION, true);