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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-07 15:53:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-07 15:53:26 -0700
commite303a067ceede918fbf90ff3dc8affbb98bad4e8 (patch)
tree13f5048bee966ccf8af6e64c3454c5d8bcc7586e
parentMerge tag 'nfsd-5.0-1' of git://linux-nfs.org/~bfields/linux (diff)
parentKVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221) (diff)
downloadlinux-dev-e303a067ceede918fbf90ff3dc8affbb98bad4e8.tar.xz
linux-dev-e303a067ceede918fbf90ff3dc8affbb98bad4e8.zip
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)
-rw-r--r--arch/x86/kvm/vmx/nested.c1
-rw-r--r--arch/x86/kvm/x86.c7
-rw-r--r--virt/kvm/kvm_main.c3
3 files changed, 10 insertions, 1 deletions
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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3d27206f6c01..e67ecf25e690 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5116,6 +5116,13 @@ int kvm_read_guest_virt(struct kvm_vcpu *vcpu,
{
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 5ecea812cb6a..585845203db8 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3000,8 +3000,10 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
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 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
return ret;
}
- kvm_get_kvm(kvm);
cd->fd = ret;
return 0;
}