From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA6F6C2D0EA for ; Wed, 8 Apr 2020 07:10:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE8F72074F for ; Wed, 8 Apr 2020 07:10:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DzdDKZ2T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726775AbgDHHKg (ORCPT ); Wed, 8 Apr 2020 03:10:36 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:56586 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726642AbgDHHKg (ORCPT ); Wed, 8 Apr 2020 03:10:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586329835; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OJEdDfDhxqWIuQHGi6+YXk/eEkMKJUcybOhiZu3aaes=; b=DzdDKZ2TicmmI7ttkkOUSMfI8J+DZfNt4uUQ0YVx+DDbrv3bhW/UKFZyZXFV6iMg+Icyc+ 5AG1XXt2aQDOa+y6mByYpxX1FsO3NMMw21zwX5HzT/v0pdF2eFaZPta3wgHnZmHHpElOlH By2dCBt4bdYLftjkdQE0dLAjVLmf2Ko= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-92-OCdvW6INMP6v5AQCkPEiRA-1; Wed, 08 Apr 2020 03:10:33 -0400 X-MC-Unique: OCdvW6INMP6v5AQCkPEiRA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 82FF98024D0; Wed, 8 Apr 2020 07:10:32 +0000 (UTC) Received: from gondolin (ovpn-113-103.ams2.redhat.com [10.36.113.103]) by smtp.corp.redhat.com (Postfix) with ESMTP id F0F931001DD8; Wed, 8 Apr 2020 07:10:27 +0000 (UTC) Date: Wed, 8 Apr 2020 09:10:24 +0200 From: Cornelia Huck To: Sean Christopherson Cc: Christian Borntraeger , Janosch Frank , Paolo Bonzini , David Hildenbrand , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+d889b59b2bb87d4047a2@syzkaller.appspotmail.com Subject: Re: [PATCH 2/2] KVM: s390: Return last valid slot if approx index is out-of-bounds Message-ID: <20200408091024.14a0d096.cohuck@redhat.com> In-Reply-To: <20200408064059.8957-3-sean.j.christopherson@intel.com> References: <20200408064059.8957-1-sean.j.christopherson@intel.com> <20200408064059.8957-3-sean.j.christopherson@intel.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 7 Apr 2020 23:40:59 -0700 Sean Christopherson wrote: > Return the index of the last valid slot from gfn_to_memslot_approx() if > its binary search loop yielded an out-of-bounds index. The index can > be out-of-bounds if the specified gfn is less than the base of the > lowest memslot (which is also the last valid memslot). > > Note, the sole caller, kvm_s390_get_cmma(), ensures used_slots is > non-zero. > This also should be cc:stable, with the dependency expressed as mentioned by Christian. > Fixes: afdad61615cc3 ("KVM: s390: Fix storage attributes migration with memory slots") > Signed-off-by: Sean Christopherson > --- > arch/s390/kvm/kvm-s390.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 19a81024fe16..5dcf9ff12828 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -1939,6 +1939,9 @@ static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn) > start = slot + 1; > } > > + if (start >= slots->used_slots) > + return slots->used_slots - 1; > + > if (gfn >= memslots[start].base_gfn && > gfn < memslots[start].base_gfn + memslots[start].npages) { > atomic_set(&slots->lru_slot, start); Reviewed-by: Cornelia Huck