From patchwork Thu Apr 16 13:23:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 227837 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 2F69FC2BB55 for ; Thu, 16 Apr 2020 13:47:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0318821734 for ; Thu, 16 Apr 2020 13:47:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044858; bh=YT2uPu+CvbKPtXH7NT0G3Z7bnBFybUw4cBTirjFdyIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rxCq4VjwHfqG37pPPPPabZ2n1KOUZN96zYyRsLDx13pPof947hYNKHTXoZplromJn ic7Jvo/vaGKaJMxQNuFqE3BhtozlUr8cdfrqw1p3mOyUYyOdVDexmM/pdclHhFDEtm d23KBKC7OWCzdFALZxpMLhIN35CzbdlmfyTQnBfM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2898688AbgDPNrf (ORCPT ); Thu, 16 Apr 2020 09:47:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:33614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2898685AbgDPNrd (ORCPT ); Thu, 16 Apr 2020 09:47:33 -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 7AA45208E4; Thu, 16 Apr 2020 13:47:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044852; bh=YT2uPu+CvbKPtXH7NT0G3Z7bnBFybUw4cBTirjFdyIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0GkmhrybmWNBXjbeB+uVkEpcSZsoqllQYl4BIzaeCewp55/g4L8CiwNn67227o7ER nc96ua3Nivd6QdngvEoc8TGZV1AM3UxEgma63bQXVdcsXrDzgbzMB/TVlvn8n8NuiL gLlkZCuRrEpGQJmi+RtiCFBXRnAXLIJnjX7SGgMk= 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 5.4 126/232] KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks Date: Thu, 16 Apr 2020 15:23:40 +0200 Message-Id: <20200416131330.817189531@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131316.640996080@linuxfoundation.org> References: <20200416131316.640996080@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 @@ -787,14 +787,18 @@ 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: