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 8328BC77B78 for ; Wed, 3 May 2023 07:34:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229696AbjECHeq (ORCPT ); Wed, 3 May 2023 03:34:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229670AbjECHem (ORCPT ); Wed, 3 May 2023 03:34:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 560AE2736; Wed, 3 May 2023 00:34:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D61A362A6D; Wed, 3 May 2023 07:34:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4127C433AE; Wed, 3 May 2023 07:34:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683099280; bh=gU+zSzWAaM1OwERIe3fE599mEpiMIC/fxdCUq8IwCYo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KwkEvJmTz0y+a+xVZqTbP/VJQB8JR6DVMGSqQNFkDClOoqX7HnzPnjKQ1GoB1gKgU I7biBf6MiGBDV2+B0V0GalrUHXs//OCC0Y9zh6lZk5+gwTOieX+NHVUqPhx2lc8x1+ aAVF5Tb1Bp8d3kDSa6xhpnnaeaKwg3NlYwvW3MXEba67vml7qpL3BUrMxWKaHmwg3Q gO1x0YraBaXFTo3aEjG4iE9b6a5u+0eLHd3Mr0RmfsXZUTp6R5Ty6wRd1bIw6V6PEP k+NzG3Vk+9SHlyMpd8UYlRAw6XTHm5AaGreaH0gRvCNKO4QMiv4SunYCUuEsD/gtWI lKnI1E9kYfpPw== Date: Wed, 3 May 2023 08:34:33 +0100 From: Lee Jones To: Sean Christopherson Cc: "gregkh@linuxfoundation.org" , Rishabh Bhatnagar , "stable@vger.kernel.org" , Suraj Jitindar Singh , Mike Bacco , "bp@alien8.de" , "mingo@redhat.com" , "tglx@linutronix.de" , "pbonzini@redhat.com" , "vkuznets@redhat.com" , "wanpengli@tencent.com" , "jmattson@google.com" , "joro@8bytes.org" , kvm@vger.kernel.org Subject: Re: [PATCH 0/9] KVM backports to 5.10 Message-ID: <20230503073433.GM620451@google.com> References: <20220909185557.21255-1-risbhat@amazon.com> <20230419071711.GA493399@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 02 May 2023, Sean Christopherson wrote: > On Wed, Apr 19, 2023, Lee Jones wrote: > > On Wed, 21 Sep 2022, gregkh@linuxfoundation.org wrote: > > > > > On Tue, Sep 20, 2022 at 06:19:26PM +0200, gregkh@linuxfoundation.org wrote: > > > > On Tue, Sep 20, 2022 at 03:34:04PM +0000, Bhatnagar, Rishabh wrote: > > > > > Gentle reminder to review this patch series. > > > > > > > > Gentle reminder to never top-post :) > > > > > > > > Also, it's up to the KVM maintainers if they wish to review this or not. > > > > I can't make them care about old and obsolete kernels like 5.10.y. Why > > > > not just use 5.15.y or newer? > > > > > > Given the lack of responses here from the KVM developers, I'll drop this > > > from my mbox and wait for them to be properly reviewed and resend before > > > considering them for a stable release. > > > > KVM maintainers, > > > > Would someone be kind enough to take a look at this for Greg please? > > > > Note that at least one of the patches in this set has been identified as > > a fix for a serious security issue regarding the compromise of guest > > kernels due to the mishandling of flush operations. > > A minor note, the security issue is serious _if_ the bug can be exploited, which > as is often the case for KVM, is a fairly big "if". Jann's PoC relied on collusion > between host userspace and the guest kernel, and as Jann called out, triggering > the bug on a !PREEMPT host kernel would be quite difficult in practice. > > I don't want to downplay the seriousness of compromising guest security, but CVSS > scores for KVM CVEs almost always fail to account for the multitude of factors in > play. E.g. CVE-2023-30456 also had a score of 7.8, and that bug required disabling > EPT, which pretty much no one does when running untrusted guest code. > > In other words, take the purported severity with a grain of salt. > > > Please could someone confirm or otherwise that this is relevant for > > v5.10.y and older? > > Acked-by: Sean Christopherson Thanks for taking the time to provide some background information and for the Ack Sean, much appreciated. For anyone taking notice, I expect a little lag on this still whilst Greg is AFK. I'll follow-up in a few days. -- Lee Jones [李琼斯]