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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0AF4C4321E for ; Mon, 7 Feb 2022 16:45:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357121AbiBGQng (ORCPT ); Mon, 7 Feb 2022 11:43:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1382083AbiBGQcD (ORCPT ); Mon, 7 Feb 2022 11:32:03 -0500 X-Greylist: delayed 62 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 07 Feb 2022 08:31:57 PST Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 28577C0401E8; Mon, 7 Feb 2022 08:31:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644251517; x=1675787517; h=message-id:date:mime-version:to:cc:references:from: subject:in-reply-to:content-transfer-encoding; bh=/KVSVa7sgjsVxefcYGnYLwrI2Vchw9qvwnAjpTnywCY=; b=nfGJGU/w8RPiJAUoDgIgE5GRiayqDpC0pLvhcOQBB17LOJ17VbcuNbnS 4kMZfObRf/qt9UtmrhIxohADZ0tWvv69NIu7vFI7X7XTNXy2grYiXCUQY gv1a5KxeeN3g+WOULH6ecpE8SEZUZOk2XN3zqWObjSO+vQt4B8Otq9MuZ vSmYr2sTwQVv8FWp4hLb83YFdw8p0o08HcW167NyCaXmgC5PWxyF27on1 v9KeNsXoWg7zyk97kJ05mavsxuCwpDJzmfD9PDeI672B/AJkjsi99T5D7 WFZ2lXWkVOuCm4eKi7IBtr08lOBREN5Jbn1fK6SSe21wod1afTwmle8K2 w==; X-IronPort-AV: E=McAfee;i="6200,9189,10250"; a="232315628" X-IronPort-AV: E=Sophos;i="5.88,350,1635231600"; d="scan'208";a="232315628" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2022 08:30:54 -0800 X-IronPort-AV: E=Sophos;i="5.88,350,1635231600"; d="scan'208";a="525193372" Received: from hgrunes-mobl1.amr.corp.intel.com (HELO [10.251.3.57]) ([10.251.3.57]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2022 08:30:53 -0800 Message-ID: <8f96c2a6-9c03-f97a-df52-73ffc1d87957@intel.com> Date: Mon, 7 Feb 2022 08:30:50 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Adrian Reber , Mike Rapoport Cc: Rick Edgecombe , x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Dave Martin , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, Andrei Vagin , Dmitry Safonov <0x7f454c46@gmail.com> References: <20220130211838.8382-1-rick.p.edgecombe@intel.com> From: Dave Hansen Subject: Re: [PATCH 00/35] Shadow stacks for userspace In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/6/22 23:20, Adrian Reber wrote: >>> CRIU Support >>> ------------ >>> In the past there was some speculation on the mailing list about >>> whether CRIU would need to be taught about CET. It turns out, it does. >>> The first issue hit is that CRIU calls sigreturn directly from its >>> “parasite code” that it injects into the dumper process. This violates >>> this shadow stack implementation’s protection that intends to prevent >>> attackers from doing this. ... >>>From the CRIU side I can say that I would definitely like to see this > resolved. CRIU just went through a similar exercise with rseq() being > enabled in glibc and CI broke all around for us and other projects > relying on CRIU. Although rseq() was around for a long time we were not > aware of it but luckily 5.13 introduced a way to handle it for CRIU with > ptrace. An environment variable existed but did not really help when > CRIU is called somewhere in the middle of the container software stack. > >>>From my point of view a solution not involving an environment variable > would definitely be preferred. Have there been things like this for CRIU in the past? Something where CRIU needs control but that's also security-sensitive? Any thoughts on how you would _like_ to see this resolved?