From patchwork Wed Apr 22 09:55:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 227335 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 06207C55186 for ; Wed, 22 Apr 2020 10:04:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF8A42075A for ; Wed, 22 Apr 2020 10:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549863; bh=Mt0JTdcemgB9LdS8YtQXlFe2GR/72wNdkTdLUMca8OE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JILiCGLoV8H4gpbj6h2hSxxPdQ9qvO6EAfd9OgRO7yoh+DBw5jJxVjAdnxYaQM5Iy n4ccInj92TOS95zwH5nPpx4plnetAPlHZL6HDvYc3UF0JSlt/7mm89OM6T/MSLlixI Xtw+jweVW94Pcl0TCA2xhTJ9rSJj90J8gk9d1ZZ4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726815AbgDVKEX (ORCPT ); Wed, 22 Apr 2020 06:04:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:54642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727996AbgDVKEU (ORCPT ); Wed, 22 Apr 2020 06:04:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 015EA20575; Wed, 22 Apr 2020 10:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549858; bh=Mt0JTdcemgB9LdS8YtQXlFe2GR/72wNdkTdLUMca8OE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CDxgg3nzG/f2+j9FCI0zqs++y9WCqx5ivQA9j5Vj+fOpSyFnThbDbjS1F5R/grtf/ tbj/lmnrNlrKBfhTm08J9hunjkUgrT6hx6BKF4t9i0ziTeC/f1tM7H4laltrPogtoY TNl3oRcUqQ07uDYemulQO6DwkEOwYgArHUw13OQE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Janosch Frank , David Hildenbrand , Claudio Imbrenda , Christian Borntraeger Subject: [PATCH 4.9 035/125] KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks Date: Wed, 22 Apr 2020 11:55:52 +0200 Message-Id: <20200422095039.116055186@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095032.909124119@linuxfoundation.org> References: <20200422095032.909124119@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Hildenbrand commit a1d032a49522cb5368e5dfb945a85899b4c74f65 upstream. In case we have a region 1 the following calculation (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11) results in 64. As shifts beyond the size are undefined the compiler is free to use instructions like sllg. sllg will only use 6 bits of the shift value (here 64) resulting in no shift at all. That means that ALL addresses will be rejected. The can result in endless loops, e.g. when prefix cannot get mapped. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank Reported-by: Janosch Frank Cc: # v4.8+ Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com Reviewed-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger [borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE] Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman --- arch/s390/mm/gmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -759,14 +759,18 @@ static void gmap_call_notifier(struct gm 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 (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: