From patchwork Fri Apr 3 15:30:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11473003 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8489414DD for ; Fri, 3 Apr 2020 15:31:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 623FB20CC7 for ; Fri, 3 Apr 2020 15:31:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WE5TVmWF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404280AbgDCPbG (ORCPT ); Fri, 3 Apr 2020 11:31:06 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55703 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404270AbgDCPbF (ORCPT ); Fri, 3 Apr 2020 11:31:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585927865; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KOB528RQaBcIIxwNxgwnDzZl9thgTK4yeE9O3dHXbMk=; b=WE5TVmWFEVinsif276lRNhAR6Yw3MkR1+AlW+l85t0gDkJzwR87b1NZs9KwVrPN2nHqyKX SYexVrF/k3tlojmj5XdIR0YEVR42Gw1IsQ5KRuMNGTpKZA5kFNcDWHJ2nDP5V/emCpbAeh JISZtdr8AZVOXNo9GXFiT6hgt3pPHog= 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-350-PkOhlhWAOjGlSOe86hgh-A-1; Fri, 03 Apr 2020 11:31:01 -0400 X-MC-Unique: PkOhlhWAOjGlSOe86hgh-A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B2F351005513; Fri, 3 Apr 2020 15:30:59 +0000 (UTC) Received: from t480s.redhat.com (ovpn-112-213.ams2.redhat.com [10.36.112.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id A79C326DC4; Fri, 3 Apr 2020 15:30:57 +0000 (UTC) From: David Hildenbrand To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Heiko Carstens , Cornelia Huck , Janosch Frank , Christian Borntraeger , David Hildenbrand , stable@vger.kernel.org Subject: [PATCH v2 1/5] KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks Date: Fri, 3 Apr 2020 17:30:46 +0200 Message-Id: <20200403153050.20569-2-david@redhat.com> In-Reply-To: <20200403153050.20569-1-david@redhat.com> References: <20200403153050.20569-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In case we have a region 1 ASCE, our shadow/g3 address can have any value. Unfortunately, (-1UL << 64) is undefined and triggers sometimes, rejecting valid shadow addresses when trying to walk our shadow table hierarchy. The result is that the prefix cannot get mapped and will loop basically forever trying to map it (-EAGAIN loop). After all, the broken check is only a sanity check, our table shadowing code in kvm_s390_shadow_tables() already checks these conditions, injecting proper translation exceptions. Turn it into a WARN_ON_ONCE(). Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank Reported-by: Janosch Frank Cc: # v4.8+ Signed-off-by: David Hildenbrand Reviewed-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda --- arch/s390/mm/gmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 2fbece47ef6f..b93dd54b234a 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -787,14 +787,18 @@ static void gmap_call_notifier(struct gmap *gmap, unsigned long start, static inline unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level) { + const int asce_type = gmap->asce & _ASCE_TYPE_MASK; unsigned long *table; if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4)) return NULL; if (gmap_is_shadow(gmap) && gmap->removed) return NULL; - if (gaddr & (-1UL << (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11))) + + if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1 && + gaddr & (-1UL << (31 + (asce_type >> 2) * 11)))) return NULL; + table = gmap->table; switch (gmap->asce & _ASCE_TYPE_MASK) { case _ASCE_TYPE_REGION1: