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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 1A9F3C433E0 for ; Thu, 28 May 2020 07:44:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E40D42145D for ; Thu, 28 May 2020 07:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590651889; bh=JQovPRzRildkfK94RqErFvrfrdiBQzI+HhRl0V5TBkU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=H6Dneav0fYUhte4I0Wzjl5IEWnrE4DLWM+sClJ8r6ftFMsb7FYS+CoMEso+8SNP0i 2BVK7UsoWaoRUfeq7cfp1KY3XFdxas3XaUEAVEbNPhsrpvwZnn4yIal9ZVUNzJ11X4 Oo/zUjHB8IOZJEGy5BOmqhu51qJwoGVQCY4E6XHY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726734AbgE1Hos (ORCPT ); Thu, 28 May 2020 03:44:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbgE1Hor (ORCPT ); Thu, 28 May 2020 03:44:47 -0400 Received: from mail-ed1-x541.google.com (mail-ed1-x541.google.com [IPv6:2a00:1450:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50473C05BD1E for ; Thu, 28 May 2020 00:44:46 -0700 (PDT) Received: by mail-ed1-x541.google.com with SMTP id g9so22376698edw.10 for ; Thu, 28 May 2020 00:44:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=MxtFmPxsx2QLpxqRiRjosE9zDHzIOqgaK1Ln9E8J5Wk=; b=MDZ0Hyla0vij8gZtFndPn/KfM/hS0wvjYUGWft1tfhbG0pU6ZGt7atfIXQ5b7b7z/T 3LyJ6Eee6zMOPIvML5uvgrpCou7YURDnmhhkJU8VgAV0SyZjh2YvWhmgalnsoThWuk4a 8NaLsKDDHpnLPjySR/rVJsr+hByzyZDhzNFlXdc9Dx16ZTmSj8xYD4fi0NAqlrw56bzF qiVDs1PfMMLBK/RIsndTpg3j71xn+LfGr28zv5+I/VOZCkIC0dyMuhuOjUmr2yLoR81p ZxuQ0UL7gi3vkE3NV8h+Kt565HWKjVarPkxF1dfOtNH4fQcSj0bQCHpqQCnyK8aQ7t2E 3MYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=MxtFmPxsx2QLpxqRiRjosE9zDHzIOqgaK1Ln9E8J5Wk=; b=Mmfg02MFrLn6QPcrGXO3VccdbbGFGWTaiiUVDfAhYEDijbRThTBSUa0/nCFA7utVyO ck9ewHraCoKBwcUlMgqE88pE+n8zcxLM7aKJzY913OsC61MgJNJgSAQj/qbN1CEOodWB a7adBi7E29nBVQdo3GoM4IlZ+aFeYt/Zuma1mUIIDHldy4OrYO4IqndE0Jhi+1zH/TZi F9qs+Be4dLlwnmoAhrcjumNnBH94nuiXljdh+K5fRaC1DK+LQExs679Ov6vT86blKxUd JZ8Ncm+L/oQ7ee4wAe2e0GOO9ZjxsI9qA+QUHxgbHNszU4Al6eS5/0RowmQZi8FlcBcw sFeA== X-Gm-Message-State: AOAM530SENogZSRhqMBPgrpM0Tcv4AtAByfLjb4NXU+ZiohTaftXPIaw cdTlR3ztEYLR0hjy0KbDQ9s= X-Google-Smtp-Source: ABdhPJzrOP9f0vBgk3VCRYh6KvIrcCjAt5BDMpQk8bcsNZIYcbVEjhcirApDUmmi6x3XRvzeU+GjZA== X-Received: by 2002:a50:8d42:: with SMTP id t2mr1705746edt.170.1590651885152; Thu, 28 May 2020 00:44:45 -0700 (PDT) Received: from gmail.com (54033286.catv.pool.telekom.hu. [84.3.50.134]) by smtp.gmail.com with ESMTPSA id q22sm4420821edg.97.2020.05.28.00.44.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2020 00:44:44 -0700 (PDT) Date: Thu, 28 May 2020 09:44:42 +0200 From: Ingo Molnar To: Al Viro Cc: Linus Torvalds , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [git pull] coredump infoleak fix Message-ID: <20200528074442.GB790247@gmail.com> References: <20200527213447.GH23230@ZenIV.linux.org.uk> <20200528070255.GA790247@gmail.com> <20200528070552.GJ23230@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200528070552.GJ23230@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Al Viro wrote: > On Thu, May 28, 2020 at 09:02:55AM +0200, Ingo Molnar wrote: > > > Looks good to me. > > > > I'm wondering, shouldn't we also zero-initialize the dump data to > > begin with? See the patch below (untested). > > Note that this hides the bug from KASAN, though ;-) And the bug > is not just infoleak - not all components are "all zeroes" in the > init state. Yeah, but is zero-init really a problem though? Wouldn't it be 'better' to have all zeroes if the dump doesn't fit? But I might be missing something ... Thanks, Ingo