This is a note to let you know that I've just added the patch titled
x86/kvm: Update spectre-v1 mitigation
to the 4.4-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:
x86-kvm-update-spectre-v1-mitigation.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Feb 23 17:23:58 CET 2018
From: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx>
Date: Fri, 23 Feb 2018 11:42:10 +0100
Subject: x86/kvm: Update spectre-v1 mitigation
To: gregkh@xxxxxxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>, Thomas Gleixner <tglx@xxxxxxxxxxxxx>, Andrew Honig <ahonig@xxxxxxxxxx>, kvm@xxxxxxxxxxxxxxx, Jim Mattson <jmattson@xxxxxxxxxx>, David Woodhouse <dwmw@xxxxxxxxxxxx>, Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx>
Message-ID: <1519382538-15143-22-git-send-email-jinpu.wangl@xxxxxxxxxxxxxxxx>
From: Dan Williams <dan.j.williams@xxxxxxxxx>
(cherry picked from 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 <dan.j.williams@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Andrew Honig <ahonig@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Jim Mattson <jmattson@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
[jwang: cherry pick to 4.4]
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -32,6 +32,7 @@
#include <linux/slab.h>
#include <linux/tboot.h>
#include <linux/hrtimer.h>
+#include <linux/nospec.h>
#include "kvm_cache_regs.h"
#include "x86.h"
@@ -827,21 +828,18 @@ 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 jinpu.wang@xxxxxxxxxxxxxxxx are
queue-4.4/x86-paravirt-remove-noreplace-paravirt-cmdline-option.patch
queue-4.4/documentation-document-array_index_nospec.patch
queue-4.4/kvm-x86-make-indirect-calls-in-emulator-speculation-safe.patch
queue-4.4/x86-nospec-fix-header-guards-names.patch
queue-4.4/x86-retpoline-avoid-retpolines-for-built-in-__init-functions.patch
queue-4.4/vfs-fdtable-prevent-bounds-check-bypass-via-speculative-execution.patch
queue-4.4/kvm-nvmx-invvpid-handling-improvements.patch
queue-4.4/x86-cpu-bugs-make-retpoline-module-warning-conditional.patch
queue-4.4/x86-spectre-check-config_retpoline-in-command-line-parser.patch
queue-4.4/x86-implement-array_index_mask_nospec.patch
queue-4.4/array_index_nospec-sanitize-speculative-array-de-references.patch
queue-4.4/kvm-vmx-make-indirect-call-speculation-safe.patch
queue-4.4/x86-spectre-fix-spelling-mistake-vunerable-vulnerable.patch
queue-4.4/kvm-nvmx-fix-kernel-panics-induced-by-illegal-invept-invvpid-types.patch
queue-4.4/module-retpoline-warn-about-missing-retpoline-in-module.patch
queue-4.4/x86-kvm-update-spectre-v1-mitigation.patch
queue-4.4/x86-get_user-use-pointer-masking-to-limit-speculation.patch
queue-4.4/x86-syscall-sanitize-syscall-table-de-references-under-speculation.patch
queue-4.4/kvm-nvmx-vmx_complete_nested_posted_interrupt-can-t-fail.patch
queue-4.4/x86-spectre-simplify-spectre_v2-command-line-parsing.patch
queue-4.4/x86-speculation-fix-typo-ibrs_att-which-should-be-ibrs_all.patch
queue-4.4/x86-spectre-report-get_user-mitigation-for-spectre_v1.patch
queue-4.4/x86-introduce-barrier_nospec.patch
queue-4.4/kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch
queue-4.4/kvm-vmx-clean-up-declaration-of-vpid-ept-invalidation-types.patch
queue-4.4/x86-bugs-drop-one-mitigation-from-dmesg.patch
queue-4.4/x86-retpoline-remove-the-esp-rsp-thunk.patch
queue-4.4/nl80211-sanitize-array-index-in-parse_txq_params.patch
queue-4.4/kvm-nvmx-kmap-can-t-fail.patch