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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9265AC282CE for ; Mon, 11 Feb 2019 14:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6076F2081B for ; Mon, 11 Feb 2019 14:38:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895905; bh=YDOL7bNZ5gzlTYR1zB3MeFJwNbUHJ3VUBEJPYBUHONI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tK7ibGgvUk0x+iCLh5X+Gv1COB6RAx8u3DW7jB2O3mBw4itDcc/Jsqj52v4tBZ9A3 LWuiUdmqP7NycxVfJo/SSH4P8hR87BYMIJHGhUahYTWyFJfHqym1sDQkR3v5BHVeHJ 1ncbCcCZAwsqdRMAqtNNK7idYyRnjNR17xb8LTIc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731105AbfBKOiX (ORCPT ); Mon, 11 Feb 2019 09:38:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:48090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730875AbfBKOiV (ORCPT ); Mon, 11 Feb 2019 09:38:21 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 89D072081B; Mon, 11 Feb 2019 14:38:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895901; bh=YDOL7bNZ5gzlTYR1zB3MeFJwNbUHJ3VUBEJPYBUHONI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SyRYKULHI91q8WRHIjjjxaKGXQ8+ouUvZJ7mOAZNdruGSmmuevIxwPaZtSN+3vfqW meQv3FdH7MOQL7AJgR/tmwKcsKxNqECsMzovzhPKwtfmtDRFQ+wA7iCd25bBiBQBfx WpQhqHFHTKiVOspkKBPVW4SJVhf7ru3WcbpeeGms= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Felix Wilhelm , stable@kernel.org, Paolo Bonzini Subject: [PATCH 4.20 339/352] KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222) Date: Mon, 11 Feb 2019 15:19:26 +0100 Message-Id: <20190211141908.744528005@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit 353c0956a618a07ba4bbe7ad00ff29fe70e8412a upstream. Bugzilla: 1671930 Emulation of certain instructions (VMXON, VMCLEAR, VMPTRLD, VMWRITE with memory operand, INVEPT, INVVPID) can incorrectly inject a page fault when passed an operand that points to an MMIO address. The page fault will use uninitialized kernel stack memory as the CR2 and error code. The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR exit to userspace; however, it is not an easy fix, so for now just ensure that the error code and CR2 are zero. Embargoed until Feb 7th 2019. Reported-by: Felix Wilhelm Cc: stable@kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5041,6 +5041,13 @@ int kvm_read_guest_virt(struct kvm_vcpu { u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; + /* + * FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED + * is returned, but our callers are not ready for that and they blindly + * call kvm_inject_page_fault. Ensure that they at least do not leak + * uninitialized kernel stack memory into cr2 and error code. + */ + memset(exception, 0, sizeof(*exception)); return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access, exception); }