From patchwork Mon Aug 16 19:57:38 2021 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: 1517320 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) 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: 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=g940Nho0; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4GpR591931z9sSn; Tue, 17 Aug 2021 06:45:48 +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 1mFilD-0000SY-GV; Mon, 16 Aug 2021 19:59:03 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1mFil7-0000Rm-NM for kernel-team@lists.ubuntu.com; Mon, 16 Aug 2021 19:58:57 +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-0.canonical.com (Postfix) with ESMTPSA id C47B23F110 for ; Mon, 16 Aug 2021 19:58:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1629143937; bh=koeFALe38UTWnq+BDOJABJyN3a5f2ypBTCwGUVUnTEY=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=g940Nho05gUI4e2V1mWcIHIXUL+2SMMYpJqVYgxEnWTCdKcKfkXpxAopLXSP10SdH DcMw6bjJREOb00oab+cJmTRwMEcM+77zWE9wxHlvxR/aT9YU5H8UthxrDQ/2aKjlfK vSdbnYn9enYAO7deOJqPfv32SYO1xLqxu26Au/EpDvppWHkP8Ouqan61W/qi+bKFFK 6AF99P686YCKxOGcmEzzV9dYz2YRpvhOfDk8m06DLct0FiTertDcQnvPcwdYYADhBN e3r9+0KBDxeG0sx8VvdClPH1xcfhwN9jZ/4MYsT13LHvd42ttIar6/XX7tUuexOf3h 0g05zqqpDzliw== From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [SRU Bionic/Focal 0/2] LP: #1940134/CVE-2021-3653 - L2 guest on AMD SVM Date: Mon, 16 Aug 2021 16:57:38 -0300 Message-Id: <20210816195742.12730-1-cascardo@canonical.com> X-Mailer: git-send-email 2.30.2 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" This patchset reverts the original fix for CVE-2021-3653, which showed the regression, and applied the fixed version that ended up upstream. The regression only showed on backports for kernels older than 5.8. And as the backport was necessary, I picked up the upstream stable v5.4.y version, which applied cleanly on both focal and bionic trees. The end result has been built and tested on an AMD system, where I was able to launch an L2 Linux guest inside an L1 Linux guest. Both versions were tested. [Impact] Users won't be able to run a Linux inside a Linux guest. [Test case] Launch an L1 guest with libvirt, then launch an L2 guest using qemu inside that first/L1 guest. [Potential regression] There might be reduced performance due to vmexits for interrupt handling. Maxim Levitsky (1): KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Thadeu Lima de Souza Cascardo (1): UBUNTU: SAUCE: Revert "UBUNTU: SAUCE: KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl" arch/x86/kvm/svm.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) Acked-by: Kamal Mostafa Acked-by: Ian May