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=-6.8 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=unavailable 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 D5BDCC5518A for ; Wed, 22 Apr 2020 10:04:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB83820B1F for ; Wed, 22 Apr 2020 10:04:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549865; bh=Mt0JTdcemgB9LdS8YtQXlFe2GR/72wNdkTdLUMca8OE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kzfR5+/Yl0dITDZD7lU89eFfTt8kjt0gCusAJMo7O1IiNEqdIkDLS6Jy8XaLWDact vitJ0pAdvkIJ5lGj2Dh+UuWLv0AKCUV6UrIipGr7FkP703UyXXWIdC24czcZq3+jjS 6V0ZCevXJAVS+KowGT4fRsRbT1Si+iQzRY+xjWj8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728012AbgDVKEZ (ORCPT ); Wed, 22 Apr 2020 06:04:25 -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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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: