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 1DAEBECAAD5 for ; Tue, 6 Sep 2022 12:08:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234241AbiIFMIL (ORCPT ); Tue, 6 Sep 2022 08:08:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239513AbiIFMHr (ORCPT ); Tue, 6 Sep 2022 08:07:47 -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 638007963B for ; Tue, 6 Sep 2022 05:07:41 -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 5A140614E1 for ; Tue, 6 Sep 2022 12:07:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67BF8C433D6; Tue, 6 Sep 2022 12:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662466059; bh=ZHPw8Lxedogcq5zOGm4w2yzRi0/BQV/4J9kwMtrO2u0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=y9ZoXwWDfJUsSiNBhvvhd7IkeNbKpZeFPUpkreDyPxmMQHPX3fiImox4+1LfH77DR uAigTacwIFpwPRYj2HFnQEnTkTt2UsXgfmGX8s07W2l6plIF6vgmTSMWfPa0CQMkXc ArhqYMFr6Z91oAy/QD/rat75CRsUQAuAx7wWqWTE= Date: Tue, 6 Sep 2022 14:07:37 +0200 From: Greg KH To: Ben Hutchings Cc: peterz@infradead.org, stable@vger.kernel.org, Daniel Sneddon , Pawan Gupta , Borislav Petkov Subject: Re: FAILED: patch "[PATCH] x86/nospec: Fix i386 RSB stuffing" failed to apply to 5.10-stable tree Message-ID: References: <166176181110563@kroah.com> <3e14d81d0576aed9583d07fbd14e6a502f2d4739.camel@decadent.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Sep 02, 2022 at 04:26:57PM +0200, Ben Hutchings wrote: > On Thu, 2022-09-01 at 11:43 +0200, Greg KH wrote: > > On Mon, Aug 29, 2022 at 04:04:58PM +0200, Ben Hutchings wrote: > > > On Mon, 2022-08-29 at 10:30 +0200, gregkh@linuxfoundation.org wrote: > > > > The patch below does not apply to the 5.10-stable tree. > > > > If someone wants it applied there, or to any other stable or longterm > > > > tree, then please email the backport, including the original git commit > > > > id to . > > > > > > > > > > You need commit 4e3aa9238277 "x86/nospec: Unwreck the RSB stuffing" > > > before this one. I've attached the backport of that for 5.10. I > > > haven't checked the older branches. > > > > Great, thanks, this worked. But the backport did not apply to 4.19, so > > I will need that in order to take this one as well. > > I've had a look at 5.4, and it's sufficiently different from upstream > that I don't see how to move forward. > > However, I also found that the PBRSB mitigation seems broken, as commit > fc02735b14ff "KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS" > was not backported (and would be hard to add). > > So, perhaps it would be best to revert the backports of: > > 2b1299322016 x86/speculation: Add RSB VM Exit protections > ba6e31af2be9 x86/speculation: Add LFENCE to RSB fill sequence > > in stable branches older than 5.10. Why? Is it because they do not work at all there, or are they causing problems? thanks, greg k-h