From patchwork Tue Aug 8 17:18:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 1818778 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=b3CYDmnE; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RL0L54xzyz1yYl for ; Wed, 9 Aug 2023 03:19:40 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1qTQMm-0006JJ-Mv; Tue, 08 Aug 2023 17:19:32 +0000 Received: from smtp-relay-canonical-1.internal ([10.131.114.174] helo=smtp-relay-canonical-1.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1qTQMl-0006JB-4r for kernel-team@lists.ubuntu.com; Tue, 08 Aug 2023 17:19:31 +0000 Received: from localhost.localdomain (1.general.cascardo.us.vpn [10.172.70.58]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id 3186C41FA2 for ; Tue, 8 Aug 2023 17:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1691515170; bh=Ya1Xb5tOOf//IjDLAokvnkmF9D67tLKmQvh7J69u5v0=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=b3CYDmnEG/srU+9/3s8r5GqM8PcQ8PdsfdXwTIgptuGyu7gu/W8jztrXQN+3FVqrv efkJzv1gy6e/ipS5BHovty6mwEUaAHGIFK7a6vE4a0oLshvs/QQ3rGK2ypVaLI0m1B HRdISNSelKv2BkATDazucsHsU7UlHKmaT6h8VTvAEdjp5xgLirtrBe3Xv+lrrvH326 9ZBAWy+612UQGhvbAyVSlukR+KPj/XuNNGZYIIZLgMLq7ZxDZgg6A47HKSCooh77GX b7gQGxQV4TlqiKpKLpx2PqqspoVLLNK23eATWDYThQYnw35Wh1zMDKOJiO1xn9ii9j 3cED+y7R4BWeA== From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [SRU OEM-6.0 0/3] CVE-2022-27672 Date: Tue, 8 Aug 2023 14:18:39 -0300 Message-Id: <20230808171842.83827-1-cascardo@canonical.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" [Impact] A VM may force the CPU to go to idle and when it gets back from idle, it could leverage the RSB from a sibling thread to mount a speculative execution attack. [Backport] Simple conflicts and the placement of setting mitigate_smt_rsb. [Potential regression] It would affect VMs, specially when dealing with idleness. Tom Lendacky (3): x86/speculation: Identify processors vulnerable to SMT RSB predictions KVM: x86: Mitigate the cross-thread return address predictions bug Documentation/hw-vuln: Add documentation for Cross-Thread Return Predictions .../admin-guide/hw-vuln/cross-thread-rsb.rst | 92 +++++++++++++++++++ Documentation/admin-guide/hw-vuln/index.rst | 1 + arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/common.c | 9 +- arch/x86/kvm/x86.c | 43 ++++++--- 5 files changed, 133 insertions(+), 13 deletions(-) create mode 100644 Documentation/admin-guide/hw-vuln/cross-thread-rsb.rst Acked-by: Cengiz Can Acked-by: Tim Gardner