diff options
Diffstat (limited to 'KVM-x86-work-around-infinite-loop-in-microcode-when-.patch')
| -rw-r--r-- | KVM-x86-work-around-infinite-loop-in-microcode-when-.patch | 92 |
1 files changed, 0 insertions, 92 deletions
diff --git a/KVM-x86-work-around-infinite-loop-in-microcode-when-.patch b/KVM-x86-work-around-infinite-loop-in-microcode-when-.patch deleted file mode 100644 index 013af11e1..000000000 --- a/KVM-x86-work-around-infinite-loop-in-microcode-when-.patch +++ /dev/null @@ -1,92 +0,0 @@ -From adceca1789584fe567828afb7246bd35a8549e94 Mon Sep 17 00:00:00 2001 -From: Eric Northup <digitaleric@google.com> -Date: Tue, 10 Nov 2015 13:22:52 +0100 -Subject: [PATCH 1/2] KVM: x86: work around infinite loop in microcode when #AC - is delivered - -It was found that a guest can DoS a host by triggering an infinite -stream of "alignment check" (#AC) exceptions. This causes the -microcode to enter an infinite loop where the core never receives -another interrupt. The host kernel panics pretty quickly due to the -effects (CVE-2015-5307). - -Signed-off-by: Eric Northup <digitaleric@google.com> -Cc: stable@vger.kernel.org -Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> ---- - arch/x86/include/uapi/asm/svm.h | 1 + - arch/x86/kvm/svm.c | 8 ++++++++ - arch/x86/kvm/vmx.c | 5 ++++- - 3 files changed, 13 insertions(+), 1 deletion(-) - -diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h -index b5d7640abc5d..8a4add8e4639 100644 ---- a/arch/x86/include/uapi/asm/svm.h -+++ b/arch/x86/include/uapi/asm/svm.h -@@ -100,6 +100,7 @@ - { SVM_EXIT_EXCP_BASE + UD_VECTOR, "UD excp" }, \ - { SVM_EXIT_EXCP_BASE + PF_VECTOR, "PF excp" }, \ - { SVM_EXIT_EXCP_BASE + NM_VECTOR, "NM excp" }, \ -+ { SVM_EXIT_EXCP_BASE + AC_VECTOR, "AC excp" }, \ - { SVM_EXIT_EXCP_BASE + MC_VECTOR, "MC excp" }, \ - { SVM_EXIT_INTR, "interrupt" }, \ - { SVM_EXIT_NMI, "nmi" }, \ -diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c -index f2c8e4917688..7203b3cc71b5 100644 ---- a/arch/x86/kvm/svm.c -+++ b/arch/x86/kvm/svm.c -@@ -1110,6 +1110,7 @@ static void init_vmcb(struct vcpu_svm *svm) - set_exception_intercept(svm, PF_VECTOR); - set_exception_intercept(svm, UD_VECTOR); - set_exception_intercept(svm, MC_VECTOR); -+ set_exception_intercept(svm, AC_VECTOR); - - set_intercept(svm, INTERCEPT_INTR); - set_intercept(svm, INTERCEPT_NMI); -@@ -1798,6 +1799,12 @@ static int ud_interception(struct vcpu_svm *svm) - return 1; - } - -+static int ac_interception(struct vcpu_svm *svm) -+{ -+ kvm_queue_exception_e(&svm->vcpu, AC_VECTOR, 0); -+ return 1; -+} -+ - static void svm_fpu_activate(struct kvm_vcpu *vcpu) - { - struct vcpu_svm *svm = to_svm(vcpu); -@@ -3362,6 +3369,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = { - [SVM_EXIT_EXCP_BASE + PF_VECTOR] = pf_interception, - [SVM_EXIT_EXCP_BASE + NM_VECTOR] = nm_interception, - [SVM_EXIT_EXCP_BASE + MC_VECTOR] = mc_interception, -+ [SVM_EXIT_EXCP_BASE + AC_VECTOR] = ac_interception, - [SVM_EXIT_INTR] = intr_interception, - [SVM_EXIT_NMI] = nmi_interception, - [SVM_EXIT_SMI] = nop_on_interception, -diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c -index 5eb56ed77c1f..106aa940d3c0 100644 ---- a/arch/x86/kvm/vmx.c -+++ b/arch/x86/kvm/vmx.c -@@ -1631,7 +1631,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) - u32 eb; - - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) | -- (1u << NM_VECTOR) | (1u << DB_VECTOR); -+ (1u << NM_VECTOR) | (1u << DB_VECTOR) | (1u << AC_VECTOR); - if ((vcpu->guest_debug & - (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) == - (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) -@@ -5266,6 +5266,9 @@ static int handle_exception(struct kvm_vcpu *vcpu) - return handle_rmode_exception(vcpu, ex_no, error_code); - - switch (ex_no) { -+ case AC_VECTOR: -+ kvm_queue_exception_e(vcpu, AC_VECTOR, error_code); -+ return 1; - case DB_VECTOR: - dr6 = vmcs_readl(EXIT_QUALIFICATION); - if (!(vcpu->guest_debug & --- -2.4.3 - |