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=-5.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 4B8E3C65BB3 for ; Mon, 10 Dec 2018 15:35:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B8B82086D for ; Mon, 10 Dec 2018 15:35:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B8B82086D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726602AbeLJPfH (ORCPT ); Mon, 10 Dec 2018 10:35:07 -0500 Received: from mga06.intel.com ([134.134.136.31]:25673 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728111AbeLJPfD (ORCPT ); Mon, 10 Dec 2018 10:35:03 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Dec 2018 07:35:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,338,1539673200"; d="scan'208";a="117157620" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga002.jf.intel.com with ESMTP; 10 Dec 2018 07:35:02 -0800 Date: Mon, 10 Dec 2018 08:32:30 -0700 From: Keith Busch To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Todd Aiken , Laurence Oberman , stable@vger.kernel.org Subject: Re: [PATCH] block: Restore tape support Message-ID: <20181210153230.GB25206@localhost.localdomain> References: <20181210030814.13235-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181210030814.13235-1-bvanassche@acm.org> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Sun, Dec 09, 2018 at 07:08:14PM -0800, Bart Van Assche wrote: > According to what I found in > https://bugzilla.kernel.org/show_bug.cgi?id=201935 patch "block: Clear > kernel memory before copying to user" broke tape access. Hence revert > that patch. Instead of reverting back to the leaking arbitrary kernel memory, why not just make a fix on top of it? This should do it: --- diff --git a/block/bio.c b/block/bio.c index c4ef8aa46452..55a5386fd431 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1262,7 +1262,8 @@ struct bio *bio_copy_user_iov(struct request_queue *q, if (ret) goto cleanup; } else { - zero_fill_bio(bio); + if (bmd->is_our_pages) + zero_fill_bio(bio); iov_iter_advance(iter, bio->bi_iter.bi_size); } --