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=-14.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D7304C433E2 for ; Thu, 10 Sep 2020 17:57:51 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0E4C920C09 for ; Thu, 10 Sep 2020 17:57:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="sokU7kz1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E4C920C09 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51944 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGQpR-0007sd-Ic for qemu-devel@archiver.kernel.org; Thu, 10 Sep 2020 13:57:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49524) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGQoX-00071t-CL; Thu, 10 Sep 2020 13:56:53 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:15968 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGQoV-0006xE-84; Thu, 10 Sep 2020 13:56:52 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08AHpRtL125353; Thu, 10 Sep 2020 13:56:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=aI2f/gxKVn+KImzNBWHZPxf91hEofhOfR6hYdeo4R/0=; b=sokU7kz1WF2QjGux2iyrtns3hienUyQoXfZ5LRjpcI2ZL4aXl8LJEHXSG3mrIta54GVF k9LUZytr/EptZ8y6QdUTmvwRgXMOCAoK/M+iV1ZtJFKDHxqS9xchH+YR2xLpEGeAKMvA udDhFzF/sEP97VlYbA4V1MgyFfOzg4G+uCiceEDETpyHPPu+FGjHPftEJi398bBqXOBo wDDmnm25qvVZVQh02tmwFR0Q71v4jV4lBQP/kgGRaTWkX5U+aTrlfvCsGnHojTtrxBBJ QbqyZRojAACT00RNor8NkMFATPkNs/hfFgVdVN3OdORo2PhH9PYikv5IzpzbAA+1BDIb bA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 33frwq83dw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Sep 2020 13:56:49 -0400 Received: from m0098416.ppops.net (m0098416.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 08AHsVXs136361; Thu, 10 Sep 2020 13:56:48 -0400 Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0b-001b2d01.pphosted.com with ESMTP id 33frwq83dg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Sep 2020 13:56:48 -0400 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 08AHqMTO024534; Thu, 10 Sep 2020 17:56:48 GMT Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by ppma03dal.us.ibm.com with ESMTP id 33c2a9ky2m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Sep 2020 17:56:48 +0000 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 08AHulXj34013622 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Sep 2020 17:56:47 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4672C28064; Thu, 10 Sep 2020 17:56:47 +0000 (GMT) Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EF7D628058; Thu, 10 Sep 2020 17:56:46 +0000 (GMT) Received: from localhost.localdomain (unknown [9.85.172.6]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTPS; Thu, 10 Sep 2020 17:56:46 +0000 (GMT) Subject: Re: [PATCH v5 3/8] s390/sclp: read sccb from mem based on provided length To: Thomas Huth , qemu-devel@nongnu.org, qemu-s390x@nongnu.org References: <20200910093655.255774-1-walling@linux.ibm.com> <20200910093655.255774-4-walling@linux.ibm.com> <02dabe89-8df2-90d4-c7f1-5ef951942639@redhat.com> From: Collin Walling Message-ID: <811e906a-689e-a53c-706e-5d6217ef3cb2@linux.ibm.com> Date: Thu, 10 Sep 2020 13:56:46 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <02dabe89-8df2-90d4-c7f1-5ef951942639@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-09-10_05:2020-09-10, 2020-09-10 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=2 bulkscore=0 priorityscore=1501 mlxscore=0 impostorscore=0 adultscore=0 malwarescore=0 clxscore=1015 phishscore=0 mlxlogscore=893 lowpriorityscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009100158 Received-SPF: pass client-ip=148.163.158.5; envelope-from=walling@linux.ibm.com; helo=mx0a-001b2d01.pphosted.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/10 13:56:49 X-ACL-Warn: Detected OS = Linux 3.x [generic] X-Spam_score_int: -62 X-Spam_score: -6.3 X-Spam_bar: ------ X-Spam_report: (-6.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-3.576, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: frankja@linux.ibm.com, mst@redhat.com, cohuck@redhat.com, david@redhat.com, pasic@linux.ibm.com, borntraeger@de.ibm.com, pbonzini@redhat.com, sumanthk@linux.ibm.com, mihajlov@linux.ibm.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 9/10/20 1:50 PM, Thomas Huth wrote: > On 10/09/2020 11.36, Collin Walling wrote: >> The header contained within the SCCB passed to the SCLP service call >> contains the actual length of the SCCB. Instead of allocating a static >> 4K size for the work sccb, let's allow for a variable size determined >> by the value in the header. The proper checks are already in place to >> ensure the SCCB length is sufficent to store a full response and that >> the length does not cross any explicitly-set boundaries. >> >> Signed-off-by: Collin Walling >> --- >> hw/s390x/event-facility.c | 2 +- >> hw/s390x/sclp.c | 58 ++++++++++++++++++++++----------------- >> include/hw/s390x/sclp.h | 2 +- >> 3 files changed, 35 insertions(+), 27 deletions(-) >> >> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c >> index 645b4080c5..ed92ce510d 100644 >> --- a/hw/s390x/event-facility.c >> +++ b/hw/s390x/event-facility.c >> @@ -213,7 +213,7 @@ static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb, >> >> event_buf = &red->ebh; >> event_buf->length = 0; >> - slen = sizeof(sccb->data); >> + slen = sccb_data_len(sccb); >> >> rc = SCLP_RC_NO_EVENT_BUFFERS_STORED; >> >> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c >> index 69a8724dc7..cb8e2e8ec3 100644 >> --- a/hw/s390x/sclp.c >> +++ b/hw/s390x/sclp.c >> @@ -231,25 +231,30 @@ int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb, >> { >> SCLPDevice *sclp = get_sclp_device(); >> SCLPDeviceClass *sclp_c = SCLP_GET_CLASS(sclp); >> - SCCB work_sccb; >> - hwaddr sccb_len = sizeof(SCCB); >> + SCCBHeader header; >> + SCCB *work_sccb; > > I'd maybe use "g_autofree SCCB *work_sccb = NULL" so you don't have to > worry about doing the g_free() later. Can do. > >> - s390_cpu_pv_mem_read(env_archcpu(env), 0, &work_sccb, sccb_len); >> + s390_cpu_pv_mem_read(env_archcpu(env), 0, &header, sizeof(SCCBHeader)); >> + >> + work_sccb = g_malloc0(header.length); > > Please use be16_to_cpu(header.length) here as well. Good catch, thanks! > >> + s390_cpu_pv_mem_read(env_archcpu(env), 0, work_sccb, >> + be16_to_cpu(header.length)); >> >> if (!sclp_command_code_valid(code)) { >> - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND); >> + work_sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND); >> goto out_write; >> } >> >> - if (!sccb_verify_boundary(sccb, work_sccb.h.length)) { >> - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); >> + if (!sccb_verify_boundary(sccb, work_sccb->h.length)) { >> + work_sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); >> goto out_write; >> } >> >> - sclp_c->execute(sclp, &work_sccb, code); >> + sclp_c->execute(sclp, work_sccb, code); >> out_write: >> - s390_cpu_pv_mem_write(env_archcpu(env), 0, &work_sccb, >> - be16_to_cpu(work_sccb.h.length)); >> + s390_cpu_pv_mem_write(env_archcpu(env), 0, work_sccb, >> + be16_to_cpu(work_sccb->h.length)); >> + g_free(work_sccb); >> sclp_c->service_interrupt(sclp, SCLP_PV_DUMMY_ADDR); >> return 0; >> } >> @@ -258,9 +263,8 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code) >> { >> SCLPDevice *sclp = get_sclp_device(); >> SCLPDeviceClass *sclp_c = SCLP_GET_CLASS(sclp); >> - SCCB work_sccb; >> - >> - hwaddr sccb_len = sizeof(SCCB); >> + SCCBHeader header; >> + SCCB *work_sccb; > > Maybe g_autofree again? > >> /* first some basic checks on program checks */ >> if (env->psw.mask & PSW_MASK_PSTATE) { >> @@ -274,33 +278,37 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code) >> return -PGM_SPECIFICATION; >> } >> >> + /* the header contains the actual length of the sccb */ >> + cpu_physical_memory_read(sccb, &header, sizeof(SCCBHeader)); >> + >> + /* Valid sccb sizes */ >> + if (be16_to_cpu(header.length) < sizeof(SCCBHeader)) { >> + return -PGM_SPECIFICATION; >> + } >> + >> /* >> * we want to work on a private copy of the sccb, to prevent guests >> * from playing dirty tricks by modifying the memory content after >> * the host has checked the values >> */ >> - cpu_physical_memory_read(sccb, &work_sccb, sccb_len); >> - >> - /* Valid sccb sizes */ >> - if (be16_to_cpu(work_sccb.h.length) < sizeof(SCCBHeader)) { >> - return -PGM_SPECIFICATION; >> - } >> + work_sccb = g_malloc0(header.length); > > Needs be16_to_cpu again. > >> + cpu_physical_memory_read(sccb, work_sccb, be16_to_cpu(header.length)); >> >> if (!sclp_command_code_valid(code)) { >> - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND); >> + work_sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND); >> goto out_write; >> } >> >> - if (!sccb_verify_boundary(sccb, work_sccb.h.length)) { >> - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); >> + if (!sccb_verify_boundary(sccb, work_sccb->h.length)) { >> + work_sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); >> goto out_write; >> } >> >> - sclp_c->execute(sclp, &work_sccb, code); >> + sclp_c->execute(sclp, work_sccb, code); >> out_write: >> - cpu_physical_memory_write(sccb, &work_sccb, >> - be16_to_cpu(work_sccb.h.length)); >> - >> + cpu_physical_memory_write(sccb, work_sccb, >> + be16_to_cpu(work_sccb->h.length)); >> + g_free(work_sccb); >> sclp_c->service_interrupt(sclp, sccb); >> >> return 0; > > Thomas > > Thanks, Thomas! -- Regards, Collin Stay safe and stay healthy