From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19F2BC4321D for ; Tue, 21 Aug 2018 05:13:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C97212172D for ; Tue, 21 Aug 2018 05:13:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C97212172D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726585AbeHUIcP (ORCPT ); Tue, 21 Aug 2018 04:32:15 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51172 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbeHUIcP (ORCPT ); Tue, 21 Aug 2018 04:32:15 -0400 Received: from localhost (5355525A.cm-6-6b.dynamic.ziggo.nl [83.85.82.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id E0023BC8; Tue, 21 Aug 2018 05:13:40 +0000 (UTC) Date: Tue, 21 Aug 2018 07:13:36 +0200 From: Greg Kroah-Hartman To: Daniel Rosenberg Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH] staging: android: ion: check for kref overflow Message-ID: <20180821051336.GA23394@kroah.com> References: <20180821013057.139644-1-drosen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180821013057.139644-1-drosen@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 20, 2018 at 06:30:57PM -0700, Daniel Rosenberg wrote: > Userspace can cause the kref to handles to increment > arbitrarily high. Ensure it does not overflow. > > Signed-off-by: Daniel Rosenberg > --- > > This patch is against 4.4. It does not apply to master due to a large > rework of ion in 4.12 which removed the affected functions altogther. > It applies from 3.18 to 4.11, although with a trivial conflict resolution > for the later branches. > 4c23cbff073f3b9b ("staging: android: ion: Remove import interface") > > drivers/staging/android/ion/ion.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c > index 374f840f31a48..11f93a6314fdb 100644 > --- a/drivers/staging/android/ion/ion.c > +++ b/drivers/staging/android/ion/ion.c > @@ -15,6 +15,7 @@ > * > */ > > +#include > #include > #include > #include > @@ -387,6 +388,15 @@ static void ion_handle_get(struct ion_handle *handle) > kref_get(&handle->ref); > } > > +/* Must hold the client lock */ > +static struct ion_handle *ion_handle_get_check_overflow( > + struct ion_handle *handle) > +{ > + if (atomic_read(&handle->ref.refcount) + 1 == 0) > + return ERR_PTR(-EOVERFLOW); > + ion_handle_get(handle); > + return handle; > +} > + > static int ion_handle_put_nolock(struct ion_handle *handle) > { > int ret; I tried to apply this patch, but it looks like you hand-edited it which made it impossible to apply. Did you do that, or did git really create this broken diff exactly as-is? Try applying this patch yourself, you will see the error. I could fix it by manually editing the diff metadata but I really shouldn't have to as that implies you did not test the patch you sent me :( thanks, greg k-h