From 826c1362e79abcd36f99092acd083b5a2d576676 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 9 Jan 2019 18:22:56 +0100 Subject: x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit 09abb5e3e5e50 ("KVM: nVMX: call kvm_skip_emulated_instruction in nested_vmx_{fail,succeed}") nested_vmx_failValid() results in kvm_skip_emulated_instruction() so doing it again in handle_vmptrld() when vmptr address is not backed is wrong, we end up advancing RIP twice. Fixes: fca91f6d60b6e ("kvm: nVMX: Set VM instruction error for VMPTRLD of unbacked page") Reported-by: Cornelia Huck Signed-off-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson Reviewed-by: Cornelia Huck Signed-off-by: Radim Krčmář --- arch/x86/kvm/vmx/nested.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 3170e291215d..2616bd2c7f2c 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4540,9 +4540,8 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) * given physical address won't match the required * VMCS12_REVISION identifier. */ - nested_vmx_failValid(vcpu, + return nested_vmx_failValid(vcpu, VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); - return kvm_skip_emulated_instruction(vcpu); } new_vmcs12 = kmap(page); if (new_vmcs12->hdr.revision_id != VMCS12_REVISION || -- cgit v1.2.3 From 3a33d030daaa7c507e1c12d5adcf828248429593 Mon Sep 17 00:00:00 2001 From: Tom Roeder Date: Thu, 24 Jan 2019 13:48:20 -0800 Subject: kvm: x86/vmx: Use kzalloc for cached_vmcs12 This changes the allocation of cached_vmcs12 to use kzalloc instead of kmalloc. This removes the information leak found by Syzkaller (see Reported-by) in this case and prevents similar leaks from happening based on cached_vmcs12. It also changes vmx_get_nested_state to copy out the full 4k VMCS12_SIZE in copy_to_user rather than only the size of the struct. Tested: rebuilt against head, booted, and ran the syszkaller repro https://syzkaller.appspot.com/text?tag=ReproC&x=174efca3400000 without observing any problems. Reported-by: syzbot+ded1696f6b50b615b630@syzkaller.appspotmail.com Fixes: 8fcc4b5923af5de58b80b53a069453b135693304 Cc: stable@vger.kernel.org Signed-off-by: Tom Roeder Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 2616bd2c7f2c..ce8153923854 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4140,11 +4140,11 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu) if (r < 0) goto out_vmcs02; - vmx->nested.cached_vmcs12 = kmalloc(VMCS12_SIZE, GFP_KERNEL); + vmx->nested.cached_vmcs12 = kzalloc(VMCS12_SIZE, GFP_KERNEL); if (!vmx->nested.cached_vmcs12) goto out_cached_vmcs12; - vmx->nested.cached_shadow_vmcs12 = kmalloc(VMCS12_SIZE, GFP_KERNEL); + vmx->nested.cached_shadow_vmcs12 = kzalloc(VMCS12_SIZE, GFP_KERNEL); if (!vmx->nested.cached_shadow_vmcs12) goto out_cached_shadow_vmcs12; @@ -5263,13 +5263,17 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, copy_shadow_to_vmcs12(vmx); } - if (copy_to_user(user_kvm_nested_state->data, vmcs12, sizeof(*vmcs12))) + /* + * Copy over the full allocated size of vmcs12 rather than just the size + * of the struct. + */ + if (copy_to_user(user_kvm_nested_state->data, vmcs12, VMCS12_SIZE)) return -EFAULT; if (nested_cpu_has_shadow_vmcs(vmcs12) && vmcs12->vmcs_link_pointer != -1ull) { if (copy_to_user(user_kvm_nested_state->data + VMCS12_SIZE, - get_shadow_vmcs12(vcpu), sizeof(*vmcs12))) + get_shadow_vmcs12(vcpu), VMCS12_SIZE)) return -EFAULT; } -- cgit v1.2.3 From 8997f657001d1ac5042d368a936987c87251c5ec Mon Sep 17 00:00:00 2001 From: Yi Wang Date: Mon, 21 Jan 2019 15:27:05 +0800 Subject: kvm: vmx: fix some -Wmissing-prototypes warnings MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We get some warnings when building kernel with W=1: arch/x86/kvm/vmx/vmx.c:426:5: warning: no previous prototype for ‘kvm_fill_hv_flush_list_func’ [-Wmissing-prototypes] arch/x86/kvm/vmx/nested.c:58:6: warning: no previous prototype for ‘init_vmcs_shadow_fields’ [-Wmissing-prototypes] Make them static to fix this. Signed-off-by: Yi Wang Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/vmx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index ce8153923854..8ff20523661b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -55,7 +55,7 @@ static u16 shadow_read_write_fields[] = { static int max_shadow_read_write_fields = ARRAY_SIZE(shadow_read_write_fields); -void init_vmcs_shadow_fields(void) +static void init_vmcs_shadow_fields(void) { int i, j; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0762fcab8fc9..8be2abbdf63f 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -423,7 +423,7 @@ static void check_ept_pointer_match(struct kvm *kvm) to_kvm_vmx(kvm)->ept_pointers_match = EPT_POINTERS_MATCH; } -int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush, +static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush, void *data) { struct kvm_tlb_range *range = data; -- cgit v1.2.3 From ecec76885bcfe3294685dc363fd1273df0d5d65f Mon Sep 17 00:00:00 2001 From: Peter Shier Date: Thu, 11 Oct 2018 11:46:46 -0700 Subject: KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221) Bugzilla: 1671904 There are multiple code paths where an hrtimer may have been started to emulate an L1 VMX preemption timer that can result in a call to free_nested without an intervening L2 exit where the hrtimer is normally cancelled. Unconditionally cancel in free_nested to cover all cases. Embargoed until Feb 7th 2019. Signed-off-by: Peter Shier Reported-by: Jim Mattson Reviewed-by: Jim Mattson Reported-by: Felix Wilhelm Cc: stable@kernel.org Message-Id: <20181011184646.154065-1-pshier@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 8ff20523661b..d8ea4ebd79e7 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -211,6 +211,7 @@ static void free_nested(struct kvm_vcpu *vcpu) if (!vmx->nested.vmxon && !vmx->nested.smm.vmxon) return; + hrtimer_cancel(&vmx->nested.preemption_timer); vmx->nested.vmxon = false; vmx->nested.smm.vmxon = false; free_vpid(vmx->nested.vpid02); -- cgit v1.2.3 From 6b1971c694975e49af302229202c0043568b1791 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Thu, 7 Feb 2019 11:42:14 +0100 Subject: x86/kvm/nVMX: read from MSR_IA32_VMX_PROCBASED_CTLS2 only when it is available SDM says MSR_IA32_VMX_PROCBASED_CTLS2 is only available "If (CPUID.01H:ECX.[5] && IA32_VMX_PROCBASED_CTLS[63])". It was found that some old cpus (namely "Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz (family: 0x6, model: 0xf, stepping: 0x6") don't have it. Add the missing check. Reported-by: Zdenek Kaspar Tested-by: Zdenek Kaspar Signed-off-by: Vitaly Kuznetsov Reviewed-by: Jim Mattson Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index d8ea4ebd79e7..8b45205b4e1d 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5557,9 +5557,11 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps, * secondary cpu-based controls. Do not include those that * depend on CPUID bits, they are added later by vmx_cpuid_update. */ - rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2, - msrs->secondary_ctls_low, - msrs->secondary_ctls_high); + if (msrs->procbased_ctls_high & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2, + msrs->secondary_ctls_low, + msrs->secondary_ctls_high); + msrs->secondary_ctls_low = 0; msrs->secondary_ctls_high &= SECONDARY_EXEC_DESC | -- cgit v1.2.3 From bc44121190aea96de171408310db3d3c87e2cc11 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 12 Feb 2019 16:42:23 -0800 Subject: KVM: nVMX: Restore a preemption timer consistency check A recently added preemption timer consistency check was unintentionally dropped when the consistency checks were being reorganized to match the SDM's ordering. Fixes: 461b4ba4c7ad ("KVM: nVMX: Move the checks for VM-Execution Control Fields to a separate helper function") Cc: Krish Sadhukhan Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 8b45205b4e1d..d737a51a53ca 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2473,6 +2473,10 @@ static int nested_check_vm_execution_controls(struct kvm_vcpu *vcpu, (nested_cpu_has_vpid(vmcs12) && !vmcs12->virtual_processor_id)) return -EINVAL; + if (!nested_cpu_has_preemption_timer(vmcs12) && + nested_cpu_has_save_preemption_timer(vmcs12)) + return -EINVAL; + if (nested_cpu_has_ept(vmcs12) && !valid_ept_address(vcpu, vmcs12->ept_pointer)) return -EINVAL; -- cgit v1.2.3