| From foo@baz Thu Dec 21 09:02:40 CET 2017 |
| From: Dmitry Vyukov <dvyukov@google.com> |
| Date: Tue, 24 Jan 2017 14:06:48 +0100 |
| Subject: kvm: fix usage of uninit spinlock in avic_vm_destroy() |
| |
| From: Dmitry Vyukov <dvyukov@google.com> |
| |
| |
| [ Upstream commit 3863dff0c3dd72984395c93b12383b393c5c3989 ] |
| |
| If avic is not enabled, avic_vm_init() does nothing and returns early. |
| However, avic_vm_destroy() still tries to destroy what hasn't been created. |
| The only bad consequence of this now is that avic_vm_destroy() uses |
| svm_vm_data_hash_lock that hasn't been initialized (and is not meant |
| to be used at all if avic is not enabled). |
| |
| Return early from avic_vm_destroy() if avic is not enabled. |
| It has nothing to destroy. |
| |
| Signed-off-by: Dmitry Vyukov <dvyukov@google.com> |
| Cc: Joerg Roedel <joro@8bytes.org> |
| Cc: Paolo Bonzini <pbonzini@redhat.com> |
| Cc: "Radim Krčmář" <rkrcmar@redhat.com> |
| Cc: David Hildenbrand <david@redhat.com> |
| Cc: kvm@vger.kernel.org |
| Cc: syzkaller@googlegroups.com |
| Reviewed-by: David Hildenbrand <david@redhat.com> |
| Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> |
| Signed-off-by: Sasha Levin <alexander.levin@verizon.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/x86/kvm/svm.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/arch/x86/kvm/svm.c |
| +++ b/arch/x86/kvm/svm.c |
| @@ -1382,6 +1382,9 @@ static void avic_vm_destroy(struct kvm * |
| unsigned long flags; |
| struct kvm_arch *vm_data = &kvm->arch; |
| |
| + if (!avic) |
| + return; |
| + |
| avic_free_vm_id(vm_data->avic_vm_id); |
| |
| if (vm_data->avic_logical_id_table_page) |