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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 E4CDEC76195 for ; Fri, 19 Jul 2019 04:04:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B52F5218A6 for ; Fri, 19 Jul 2019 04:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509081; bh=Wt/gn8m83bZpyLcVa1ftJFsQb6lYMfvE8ePzwf81kV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jPKc6ii7PVtHOGvIYbokVvfSE1XFpxqu/RSuV/DbPAQec/43hBvx9L1N7oLuH66PK LmsM5EDj8Mtz/ma5tBV5Yye87IkW/g2qIcE8V8QXniCQEgdNVSpm6+JRUb0KlCKgwW gSNfOfUnWhDCOj6k+H87kMRPm1TQJN/uafRr1jAc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731177AbfGSEEk (ORCPT ); Fri, 19 Jul 2019 00:04:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:36802 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731098AbfGSEEc (ORCPT ); Fri, 19 Jul 2019 00:04:32 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 91B8E218BB; Fri, 19 Jul 2019 04:04:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509071; bh=Wt/gn8m83bZpyLcVa1ftJFsQb6lYMfvE8ePzwf81kV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uH5Erg4J7RjhUrakMzf7Y6U2i5m2BG3GI2mZZwuSP7PH1FOTiGJQ5ii273C0zv6fH uFePtrJMEE6Piab1ZFzUWEue7Ccf2Z7ylFfWALRDAweaGWyHDuZhiNKmzNwU3LlhRs 9hvViaTYr9ODXCDv8Ry11XDTIyMlOdORqSFkek+g= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eugene Korenevsky , Paolo Bonzini , Sasha Levin , kvm@vger.kernel.org Subject: [PATCH AUTOSEL 5.1 053/141] kvm: vmx: fix limit checking in get_vmx_mem_address() Date: Fri, 19 Jul 2019 00:01:18 -0400 Message-Id: <20190719040246.15945-53-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719040246.15945-1-sashal@kernel.org> References: <20190719040246.15945-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eugene Korenevsky [ Upstream commit c1a9acbc5295e278d788e9f7510f543bc9864fa2 ] Intel SDM vol. 3, 5.3: The processor causes a general-protection exception (or, if the segment is SS, a stack-fault exception) any time an attempt is made to access the following addresses in a segment: - A byte at an offset greater than the effective limit - A word at an offset greater than the (effective-limit – 1) - A doubleword at an offset greater than the (effective-limit – 3) - A quadword at an offset greater than the (effective-limit – 7) Therefore, the generic limit checking error condition must be exn = (off > limit + 1 - access_len) = (off + access_len - 1 > limit) but not exn = (off + access_len > limit) as for now. Also avoid integer overflow of `off` at 32-bit KVM by casting it to u64. Note: access length is currently sizeof(u64) which is incorrect. This will be fixed in the subsequent patch. Signed-off-by: Eugene Korenevsky Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 4ca834d22169..897ae4b62980 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4143,7 +4143,7 @@ int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification, */ if (!(s.base == 0 && s.limit == 0xffffffff && ((s.type & 8) || !(s.type & 4)))) - exn = exn || (off + sizeof(u64) > s.limit); + exn = exn || ((u64)off + sizeof(u64) - 1 > s.limit); } if (exn) { kvm_queue_exception_e(vcpu, -- 2.20.1