From: Dmitry Vyukov Date: Tue, 24 Jan 2017 13:06:48 +0000 (+0100) Subject: kvm: fix usage of uninit spinlock in avic_vm_destroy() X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~570 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=2a7eee3d72b043d68af4098665eee89893386445;p=linux-4.9.git kvm: fix usage of uninit spinlock in avic_vm_destroy() [ 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 Cc: Joerg Roedel Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: David Hildenbrand Cc: kvm@vger.kernel.org Cc: syzkaller@googlegroups.com Reviewed-by: David Hildenbrand Signed-off-by: Radim Krčmář Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 23f1a6bd7a0d..8148d8ca7930 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1382,6 +1382,9 @@ static void avic_vm_destroy(struct kvm *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)