diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0002-kvm-vmx-Scrub-hardware-GPRs-at-VM-exit.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0002-kvm-vmx-Scrub-hardware-GPRs-at-VM-exit.patch | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-kvm-vmx-Scrub-hardware-GPRs-at-VM-exit.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-kvm-vmx-Scrub-hardware-GPRs-at-VM-exit.patch new file mode 100644 index 00000000..406a79d3 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-kvm-vmx-Scrub-hardware-GPRs-at-VM-exit.patch @@ -0,0 +1,97 @@ +From 1cd771013c357075c745f99419bdaf31503c5a51 Mon Sep 17 00:00:00 2001 +From: Jim Mattson <jmattson@google.com> +Date: Wed, 3 Jan 2018 14:31:38 -0800 +Subject: [PATCH 02/33] kvm: vmx: Scrub hardware GPRs at VM-exit + +commit 0cb5b30698fdc8f6b4646012e3acb4ddce430788 upstream. + +Guest GPR values are live in the hardware GPRs at VM-exit. Do not +leave any guest values in hardware GPRs after the guest GPR values are +saved to the vcpu_vmx structure. + +This is a partial mitigation for CVE 2017-5715 and CVE 2017-5753. +Specifically, it defeats the Project Zero PoC for CVE 2017-5715. + +Suggested-by: Eric Northup <digitaleric@google.com> +Signed-off-by: Jim Mattson <jmattson@google.com> +Reviewed-by: Eric Northup <digitaleric@google.com> +Reviewed-by: Benjamin Serebrin <serebrin@google.com> +Reviewed-by: Andrew Honig <ahonig@google.com> +[Paolo: Add AMD bits, Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>] +Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kvm/svm.c | 19 +++++++++++++++++++ + arch/x86/kvm/vmx.c | 14 +++++++++++++- + 2 files changed, 32 insertions(+), 1 deletion(-) + +diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c +index 975ea99..491f077 100644 +--- a/arch/x86/kvm/svm.c ++++ b/arch/x86/kvm/svm.c +@@ -4858,6 +4858,25 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) + "mov %%r14, %c[r14](%[svm]) \n\t" + "mov %%r15, %c[r15](%[svm]) \n\t" + #endif ++ /* ++ * Clear host registers marked as clobbered to prevent ++ * speculative use. ++ */ ++ "xor %%" _ASM_BX ", %%" _ASM_BX " \n\t" ++ "xor %%" _ASM_CX ", %%" _ASM_CX " \n\t" ++ "xor %%" _ASM_DX ", %%" _ASM_DX " \n\t" ++ "xor %%" _ASM_SI ", %%" _ASM_SI " \n\t" ++ "xor %%" _ASM_DI ", %%" _ASM_DI " \n\t" ++#ifdef CONFIG_X86_64 ++ "xor %%r8, %%r8 \n\t" ++ "xor %%r9, %%r9 \n\t" ++ "xor %%r10, %%r10 \n\t" ++ "xor %%r11, %%r11 \n\t" ++ "xor %%r12, %%r12 \n\t" ++ "xor %%r13, %%r13 \n\t" ++ "xor %%r14, %%r14 \n\t" ++ "xor %%r15, %%r15 \n\t" ++#endif + "pop %%" _ASM_BP + : + : [svm]"a"(svm), +diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c +index 4ead27f..91ae4e2 100644 +--- a/arch/x86/kvm/vmx.c ++++ b/arch/x86/kvm/vmx.c +@@ -8932,6 +8932,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) + /* Save guest registers, load host registers, keep flags */ + "mov %0, %c[wordsize](%%" _ASM_SP ") \n\t" + "pop %0 \n\t" ++ "setbe %c[fail](%0)\n\t" + "mov %%" _ASM_AX ", %c[rax](%0) \n\t" + "mov %%" _ASM_BX ", %c[rbx](%0) \n\t" + __ASM_SIZE(pop) " %c[rcx](%0) \n\t" +@@ -8948,12 +8949,23 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) + "mov %%r13, %c[r13](%0) \n\t" + "mov %%r14, %c[r14](%0) \n\t" + "mov %%r15, %c[r15](%0) \n\t" ++ "xor %%r8d, %%r8d \n\t" ++ "xor %%r9d, %%r9d \n\t" ++ "xor %%r10d, %%r10d \n\t" ++ "xor %%r11d, %%r11d \n\t" ++ "xor %%r12d, %%r12d \n\t" ++ "xor %%r13d, %%r13d \n\t" ++ "xor %%r14d, %%r14d \n\t" ++ "xor %%r15d, %%r15d \n\t" + #endif + "mov %%cr2, %%" _ASM_AX " \n\t" + "mov %%" _ASM_AX ", %c[cr2](%0) \n\t" + ++ "xor %%eax, %%eax \n\t" ++ "xor %%ebx, %%ebx \n\t" ++ "xor %%esi, %%esi \n\t" ++ "xor %%edi, %%edi \n\t" + "pop %%" _ASM_BP "; pop %%" _ASM_DX " \n\t" +- "setbe %c[fail](%0) \n\t" + ".pushsection .rodata \n\t" + ".global vmx_return \n\t" + "vmx_return: " _ASM_PTR " 2b \n\t" +-- +2.7.4 + |