From patchwork Tue Apr 7 11:42:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 11477963 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 DA9EA159A for ; Tue, 7 Apr 2020 11:42:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C395C2063A for ; Tue, 7 Apr 2020 11:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728213AbgDGLmt (ORCPT ); Tue, 7 Apr 2020 07:42:49 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44900 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728146AbgDGLmt (ORCPT ); Tue, 7 Apr 2020 07:42:49 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 037BYbOF078955 for ; Tue, 7 Apr 2020 07:42:48 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 3082pebmax-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 Apr 2020 07:42:48 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 7 Apr 2020 12:42:16 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 037Bgfj450659438 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 Apr 2020 11:42:41 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AF01F42042; Tue, 7 Apr 2020 11:42:41 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 85D8F4203F; Tue, 7 Apr 2020 11:42:41 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 7 Apr 2020 11:42:41 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id 46CD8E08E5; Tue, 7 Apr 2020 13:42:41 +0200 (CEST) From: Christian Borntraeger To: Paolo Bonzini Cc: KVM , Janosch Frank , David Hildenbrand , Cornelia Huck , linux-s390 , Christian Borntraeger , Janosch Frank , Claudio Imbrenda Subject: [GIT PULL 1/3] KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks Date: Tue, 7 Apr 2020 13:42:38 +0200 X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200407114240.156419-1-borntraeger@de.ibm.com> References: <20200407114240.156419-1-borntraeger@de.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 20040711-0020-0000-0000-000003C34280 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20040711-0021-0000-0000-0000221C0030 Message-Id: <20200407114240.156419-2-borntraeger@de.ibm.com> X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-07_03:2020-04-07,2020-04-07 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxscore=0 clxscore=1015 spamscore=0 lowpriorityscore=0 malwarescore=0 phishscore=0 adultscore=0 mlxlogscore=999 suspectscore=0 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004070095 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: David Hildenbrand 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 --- 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..7e9a6761f254 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 (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: