Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Three security fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 8ff2052..d8ea4eb 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -211,6 +211,7 @@
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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3d27206..e67ecf2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5116,6 +5116,13 @@
{
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
+ /*
+ * FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED
+ * is returned, but our callers are not ready for that and they blindly
+ * call kvm_inject_page_fault. Ensure that they at least do not leak
+ * uninitialized kernel stack memory into cr2 and error code.
+ */
+ memset(exception, 0, sizeof(*exception));
return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access,
exception);
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5ecea81..5858452 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3000,8 +3000,10 @@
if (ops->init)
ops->init(dev);
+ kvm_get_kvm(kvm);
ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
if (ret < 0) {
+ kvm_put_kvm(kvm);
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
mutex_unlock(&kvm->lock);
@@ -3009,7 +3011,6 @@
return ret;
}
- kvm_get_kvm(kvm);
cd->fd = ret;
return 0;
}