diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java index 64d30158b2609..766fae64f6479 100644 --- a/services/core/java/com/android/server/pm/PackageManagerService.java +++ b/services/core/java/com/android/server/pm/PackageManagerService.java @@ -148,6 +148,8 @@ import android.app.ResourcesManager; import android.app.admin.IDevicePolicyManager; import android.app.admin.SecurityLog; import android.app.backup.IBackupManager; +import android.compat.annotation.ChangeId; +import android.compat.annotation.EnabledAfter; import android.content.BroadcastReceiver; import android.content.ComponentName; import android.content.ContentResolver; @@ -639,6 +641,19 @@ public class PackageManagerService extends IPackageManager.Stub */ private static final int DEFAULT_VERIFICATION_RESPONSE = PackageManager.VERIFICATION_ALLOW; + /** + * Adding an installer package name to a package that does not have one set requires the + * INSTALL_PACKAGES permission. + * + * If the caller targets R, this will throw a SecurityException. Otherwise the request will + * fail silently. In both cases, and regardless of whether this change is enabled, the + * installer package will remain unchanged. + */ + @ChangeId + @EnabledAfter(targetSdkVersion = Build.VERSION_CODES.Q) + private static final long THROW_EXCEPTION_ON_REQUIRE_INSTALL_PACKAGES_TO_ADD_INSTALLER_PACKAGE = + 150857253; + public static final String PLATFORM_PACKAGE_NAME = "android"; private static final String PACKAGE_MIME_TYPE = "application/vnd.android.package-archive"; @@ -14172,19 +14187,38 @@ public class PackageManagerService extends IPackageManager.Stub // be signed with the same cert as the caller. String targetInstallerPackageName = targetPackageSetting.installSource.installerPackageName; - if (targetInstallerPackageName != null) { - PackageSetting setting = mSettings.mPackages.get( - targetInstallerPackageName); - // If the currently set package isn't valid, then it's always - // okay to change it. - if (setting != null) { - if (compareSignatures(callerSignature, - setting.signatures.mSigningDetails.signatures) - != PackageManager.SIGNATURE_MATCH) { - throw new SecurityException( - "Caller does not have same cert as old installer package " - + targetInstallerPackageName); + PackageSetting targetInstallerPkgSetting = targetInstallerPackageName == null ? null : + mSettings.mPackages.get(targetInstallerPackageName); + + if (targetInstallerPkgSetting != null) { + if (compareSignatures(callerSignature, + targetInstallerPkgSetting.signatures.mSigningDetails.signatures) + != PackageManager.SIGNATURE_MATCH) { + throw new SecurityException( + "Caller does not have same cert as old installer package " + + targetInstallerPackageName); + } + } else if (mContext.checkCallingOrSelfPermission(Manifest.permission.INSTALL_PACKAGES) + != PackageManager.PERMISSION_GRANTED) { + // This is probably an attempt to exploit vulnerability b/150857253 of taking + // privileged installer permissions when the installer has been uninstalled or + // was never set. + EventLog.writeEvent(0x534e4554, "150857253", callingUid, ""); + + long binderToken = Binder.clearCallingIdentity(); + try { + if (mInjector.getCompatibility().isChangeEnabledByUid( + THROW_EXCEPTION_ON_REQUIRE_INSTALL_PACKAGES_TO_ADD_INSTALLER_PACKAGE, + callingUid)) { + throw new SecurityException("Neither user " + callingUid + + " nor current process has " + + Manifest.permission.INSTALL_PACKAGES); + } else { + // If change disabled, fail silently for backwards compatibility + return; } + } finally { + Binder.restoreCallingIdentity(binderToken); } }