From patchwork Fri Oct 2 12:11:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 303858 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=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS 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 01C5FC4363D for ; Fri, 2 Oct 2020 12:20:45 +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 84176206FA for ; Fri, 2 Oct 2020 12:20:44 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Fri, 2 Oct 2020 12:11:33 +0000 (UTC) Received: from localhost (ovpn-112-216.ams2.redhat.com [10.36.112.216]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3EB3219C66; Fri, 2 Oct 2020 12:11:33 +0000 (UTC) From: Cornelia Huck To: Peter Maydell Subject: [PULL 04/19] s390/sclp: read sccb from mem based on provided length Date: Fri, 2 Oct 2020 14:11:03 +0200 Message-Id: <20201002121118.180315-5-cohuck@redhat.com> In-Reply-To: <20201002121118.180315-1-cohuck@redhat.com> References: <20201002121118.180315-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=cohuck@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/02 01:13:31 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Thomas Huth , Cornelia Huck , qemu-devel@nongnu.org, qemu-s390x@nongnu.org, Claudio Imbrenda , Collin Walling Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Collin Walling 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 Reviewed-by: Thomas Huth Reviewed-by: Claudio Imbrenda Message-Id: <20200915194416.107460-4-walling@linux.ibm.com> Signed-off-by: Cornelia Huck --- hw/s390x/event-facility.c | 2 +- hw/s390x/sclp.c | 55 ++++++++++++++++++++++----------------- include/hw/s390x/sclp.h | 2 +- 3 files changed, 33 insertions(+), 26 deletions(-) diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c index 645b4080c5b9..ed92ce510d9e 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 a37cfbf534cd..4ae6fb400b40 100644 --- a/hw/s390x/sclp.c +++ b/hw/s390x/sclp.c @@ -231,25 +231,29 @@ 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; + g_autofree SCCB *work_sccb = NULL; - 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(be16_to_cpu(header.length)); + 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, be16_to_cpu(work_sccb.h.length))) { - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); + if (!sccb_verify_boundary(sccb, be16_to_cpu(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)); sclp_c->service_interrupt(sclp, SCLP_PV_DUMMY_ADDR); return 0; } @@ -258,9 +262,8 @@ 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; + g_autofree SCCB *work_sccb = NULL; /* first some basic checks on program checks */ if (env->psw.mask & PSW_MASK_PSTATE) { @@ -274,32 +277,36 @@ 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(be16_to_cpu(header.length)); + 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, be16_to_cpu(work_sccb.h.length))) { - work_sccb.h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION); + if (!sccb_verify_boundary(sccb, be16_to_cpu(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)); sclp_c->service_interrupt(sclp, sccb); diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h index cd730772f94b..374ea83e7811 100644 --- a/include/hw/s390x/sclp.h +++ b/include/hw/s390x/sclp.h @@ -178,7 +178,7 @@ typedef struct IoaCfgSccb { typedef struct SCCB { SCCBHeader h; - char data[SCCB_DATA_LEN]; + char data[]; } QEMU_PACKED SCCB; #define TYPE_SCLP "sclp"