From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2700330-1516320817-2-7262239394723183870 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES unknown, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='utf-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1516320817; b=lNQJJTtY645HMMf9Fx6c7IIdA2yY0pg9dS2z2BBsk7ylLUe IGBN9G72OqxFK4IWolgSI/bGTOu0kleMJrpWkEPeFpwiVzpdaI03lsYhlfJuZNXo ZFDVQ1+1gS9XIgJNmmpZEtz6OjoOKWHANqVohMReJjbI2Xvk3UhlrcBjCobMPsPX yQDSYCC3IDAR6J1eGdFtHp7MHGKEaI4uMCI+bTrbE/rBSQkRCMkSXGU9B0ILXYXj WexDrXWffMkQF1qfsnpDwdEfPYapQZQK6yy2TbJ6XtYZ4OWxE7xvkiI7kWhRDZja 68AkBWq8zxrCflacYceENrCfWIBHenY/UhGnJVQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=subject:from:to:cc:date:message-id :in-reply-to:references:mime-version:content-type :content-transfer-encoding:sender:list-id; s=arctest; t= 1516320817; bh=6DbMM69/4k6ZbBPlyCYT3kxyeyXZ352te6BBIL3YS18=; b=v MQezrhpHuVrTTpp0zWp36foKvb/6D4wTumfS8GOrdIITrmJGKF9EyDoYc3RQFFMB Xsz2crxCmRkdPn0poZBtYMzXVifXsKBAm/6omGmbYbm1B2/N6hKuk9rNTBxHz7uk AmUQwUCGl6ioptCXOyt86EJH/zP/Ak7n4MG4Qfsx3wmXyVAO76x7vfbVRdo58HOw jUpRRUZotpkk3fcA/f+vJg/xmunDYYCaBqIPKSOL8o6x3LuI00012qHXSlvn+P/G QYUPYw/kqvZAJJQJ+zU3ybkGrRS0fiAIdWpDR+JfPDe5efkWNHznYNSOn2kpK6JA za+azAKo7kUqetN3uzjmA== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=intel.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=intel.com header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=intel.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=intel.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932605AbeASAMj (ORCPT ); Thu, 18 Jan 2018 19:12:39 -0500 Received: from mga14.intel.com ([192.55.52.115]:45997 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755093AbeASALh (ORCPT ); Thu, 18 Jan 2018 19:11:37 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,379,1511856000"; d="scan'208";a="194522002" Subject: [PATCH v4 09/10] kvm, x86: fix spectre-v1 mitigation From: Dan Williams To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com, Andrew Honig , stable@vger.kernel.org, gregkh@linuxfoundation.org, Paolo Bonzini , tglx@linutronix.de, alan@linux.intel.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, Jim Mattson Date: Thu, 18 Jan 2018 16:02:31 -0800 Message-ID: <151632015123.21271.9060883997507739532.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup" added a raw 'asm("lfence");' to prevent a bounds check bypass of 'vmcs_field_to_offset_table'. This does not work for some AMD cpus, see the 'ifence' helper, and it otherwise does not use the common 'array_ptr' helper designed for these types of fixes. Convert this to use 'array_ptr'. Cc: Andrew Honig Cc: Jim Mattson Cc: Paolo Bonzini Cc: Signed-off-by: Dan Williams --- arch/x86/kvm/vmx.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c829d89e2e63..20b9b0b5e336 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "kvm_cache_regs.h" #include "x86.h" @@ -898,21 +899,15 @@ static const unsigned short vmcs_field_to_offset_table[] = { static inline short vmcs_field_to_offset(unsigned long field) { - BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX); - - if (field >= ARRAY_SIZE(vmcs_field_to_offset_table)) - return -ENOENT; + const unsigned short *offset; - /* - * FIXME: Mitigation for CVE-2017-5753. To be replaced with a - * generic mechanism. - */ - asm("lfence"); + BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX); - if (vmcs_field_to_offset_table[field] == 0) + offset = array_ptr(vmcs_field_to_offset_table, field, + ARRAY_SIZE(vmcs_field_to_offset_table)); + if (!offset || *offset == 0) return -ENOENT; - - return vmcs_field_to_offset_table[field]; + return *offset; } static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu) From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Date: Thu, 18 Jan 2018 16:02:31 -0800 Message-ID: <151632015123.21271.9060883997507739532.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [kernel-hardening] [PATCH v4 09/10] kvm, x86: fix spectre-v1 mitigation To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com, Andrew Honig , stable@vger.kernel.org, gregkh@linuxfoundation.org, Paolo Bonzini , tglx@linutronix.de, alan@linux.intel.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, Jim Mattson List-ID: Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup" added a raw 'asm("lfence");' to prevent a bounds check bypass of 'vmcs_field_to_offset_table'. This does not work for some AMD cpus, see the 'ifence' helper, and it otherwise does not use the common 'array_ptr' helper designed for these types of fixes. Convert this to use 'array_ptr'. Cc: Andrew Honig Cc: Jim Mattson Cc: Paolo Bonzini Cc: Signed-off-by: Dan Williams --- arch/x86/kvm/vmx.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c829d89e2e63..20b9b0b5e336 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "kvm_cache_regs.h" #include "x86.h" @@ -898,21 +899,15 @@ static const unsigned short vmcs_field_to_offset_table[] = { static inline short vmcs_field_to_offset(unsigned long field) { - BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX); - - if (field >= ARRAY_SIZE(vmcs_field_to_offset_table)) - return -ENOENT; + const unsigned short *offset; - /* - * FIXME: Mitigation for CVE-2017-5753. To be replaced with a - * generic mechanism. - */ - asm("lfence"); + BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX); - if (vmcs_field_to_offset_table[field] == 0) + offset = array_ptr(vmcs_field_to_offset_table, field, + ARRAY_SIZE(vmcs_field_to_offset_table)); + if (!offset || *offset == 0) return -ENOENT; - - return vmcs_field_to_offset_table[field]; + return *offset; } static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)