From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60288 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753417AbeBERin (ORCPT ); Mon, 5 Feb 2018 12:38:43 -0500 Subject: Patch "x86/kvm: Update spectre-v1 mitigation" has been added to the 4.14-stable tree To: dan.j.williams@intel.com, ahonig@google.com, gregkh@linuxfoundation.org, jmattson@google.com, pbonzini@redhat.com, tglx@linutronix.de Cc: , From: Date: Mon, 05 Feb 2018 09:38:29 -0800 Message-ID: <151785230961188@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/kvm: Update spectre-v1 mitigation to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86kvm_Update_spectre-v1_mitigation.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. Subject: x86/kvm: Update spectre-v1 mitigation From: Dan Williams dan.j.williams@intel.com Date: Wed Jan 31 17:47:03 2018 -0800 From: Dan Williams dan.j.williams@intel.com commit 085331dfc6bbe3501fb936e657331ca943827600 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'. The lfence can be avoided in this path by using the array_index_nospec() helper designed for these types of fixes. Signed-off-by: Dan Williams Signed-off-by: Thomas Gleixner Acked-by: Paolo Bonzini Cc: Andrew Honig Cc: kvm@vger.kernel.org Cc: Jim Mattson Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) --- 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" @@ -887,21 +888,18 @@ static const unsigned short vmcs_field_t static inline short vmcs_field_to_offset(unsigned long field) { - BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX); + const size_t size = ARRAY_SIZE(vmcs_field_to_offset_table); + unsigned short offset; - if (field >= ARRAY_SIZE(vmcs_field_to_offset_table)) + BUILD_BUG_ON(size > SHRT_MAX); + if (field >= size) return -ENOENT; - /* - * FIXME: Mitigation for CVE-2017-5753. To be replaced with a - * generic mechanism. - */ - asm("lfence"); - - if (vmcs_field_to_offset_table[field] == 0) + field = array_index_nospec(field, size); + offset = vmcs_field_to_offset_table[field]; + if (offset == 0) return -ENOENT; - - return vmcs_field_to_offset_table[field]; + return offset; } static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu) Patches currently in stable-queue which might be from dan.j.williams@intel.com are queue-4.14/x86kvm_Update_spectre-v1_mitigation.patch queue-4.14/x86_Introduce_barrier_nospec.patch queue-4.14/x86get_user_Use_pointer_masking_to_limit_speculation.patch queue-4.14/x86_Introduce___uaccess_begin_nospec()_and_uaccess_try_nospec.patch queue-4.14/x86paravirt_Remove_noreplace-paravirt_cmdline_option.patch queue-4.14/KVM_VMX_Make_indirect_call_speculation_safe.patch queue-4.14/KVMVMX_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/array_index_nospec_Sanitize_speculative_array_de-references.patch queue-4.14/Documentation_Document_array_index_nospec.patch queue-4.14/KVMSVM_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/KVMx86_Add_IBPB_support.patch queue-4.14/x86_Implement_array_index_mask_nospec.patch queue-4.14/KVMVMX_Emulate_MSR_IA32_ARCH_CAPABILITIES.patch queue-4.14/nl80211_Sanitize_array_index_in_parse_txq_params.patch queue-4.14/KVM_x86_Make_indirect_calls_in_emulator_speculation_safe.patch queue-4.14/x86uaccess_Use___uaccess_begin_nospec()_and_uaccess_try_nospec.patch queue-4.14/x86usercopy_Replace_open_coded_stacclac_with___uaccess_begin_end.patch queue-4.14/vfs_fdtable_Prevent_bounds-check_bypass_via_speculative_execution.patch queue-4.14/x86spectre_Report_get_user_mitigation_for_spectre_v1.patch queue-4.14/x86syscall_Sanitize_syscall_table_de-references_under_speculation.patch