{"id":2224040,"url":"http://patchwork.ozlabs.org/api/patches/2224040/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260416155421.9876-1-Jonathan.Cameron@huawei.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260416155421.9876-1-Jonathan.Cameron@huawei.com>","list_archive_url":null,"date":"2026-04-16T15:54:21","name":"[qemu] hw/cxl: Avoid out of bounds read when userspace requests data off end of CDAT.","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"dcd4276d6b95ac0f391d732cb0b4c16670d8669a","submitter":{"id":71988,"url":"http://patchwork.ozlabs.org/api/people/71988/?format=json","name":"Jonathan Cameron","email":"Jonathan.Cameron@huawei.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260416155421.9876-1-Jonathan.Cameron@huawei.com/mbox/","series":[{"id":500183,"url":"http://patchwork.ozlabs.org/api/series/500183/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=500183","date":"2026-04-16T15:54:21","name":"[qemu] hw/cxl: Avoid out of bounds read when userspace requests data off end of CDAT.","version":1,"mbox":"http://patchwork.ozlabs.org/series/500183/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2224040/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2224040/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":"legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)","Received":["from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fxMzV0HBmz1yHP\n\tfor ; Fri, 17 Apr 2026 01:55:16 +1000 (AEST)","from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from )\n\tid 1wDP38-0002LT-0o; Thu, 16 Apr 2026 11:54:38 -0400","from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from )\n id 1wDP36-0002Ik-OL\n for qemu-devel@nongnu.org; Thu, 16 Apr 2026 11:54:36 -0400","from frasgout.his.huawei.com ([185.176.79.56])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from )\n id 1wDP33-00040T-VZ\n for qemu-devel@nongnu.org; Thu, 16 Apr 2026 11:54:36 -0400","from mail.maildlp.com (unknown [172.18.224.107])\n by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fxMy40wsfzHnGkW;\n Thu, 16 Apr 2026 23:54:04 +0800 (CST)","from dubpeml500005.china.huawei.com (unknown [7.214.145.207])\n by mail.maildlp.com (Postfix) with ESMTPS id 6E3A240584;\n Thu, 16 Apr 2026 23:54:22 +0800 (CST)","from SecurePC-101-06.huawei.com (10.123.51.176) by\n dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server\n (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id\n 15.2.1544.11; Thu, 16 Apr 2026 16:54:21 +0100"],"To":", , ,\n ","CC":", ","Subject":"[PATCH qemu] hw/cxl: Avoid out of bounds read when userspace requests\n data off end of CDAT.","Date":"Thu, 16 Apr 2026 16:54:21 +0100","Message-ID":"<20260416155421.9876-1-Jonathan.Cameron@huawei.com>","X-Mailer":"git-send-email 2.51.0","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Content-Type":"text/plain","X-Originating-IP":"[10.123.51.176]","X-ClientProxiedBy":"lhrpeml100010.china.huawei.com (7.191.174.197) To\n dubpeml500005.china.huawei.com (7.214.145.207)","Received-SPF":"pass client-ip=185.176.79.56;\n envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com","X-Spam_score_int":"-41","X-Spam_score":"-4.2","X-Spam_bar":"----","X-Spam_report":"(-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3,\n RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n 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":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Reply-to":"Jonathan Cameron ","From":"Jonathan Cameron via qemu development ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"The requested entry is controlled by the guest so must be checked against\nthe number of entries that actually exist.\n\nReported as a security issue, but CXL emulation has since been declared\nto not be suitable (yet) for virtualization use cases and so the security\nhandling policy does not apply.\n\nFixes: f5ee7413d592 (\"hw/mem/cxl-type3: Add CXL CDAT Data Object Exchange\")\nFixes: 882877fc359d (\"hw/pci-bridge/cxl-upstream: Add a CDAT table access DOE\")\nReported-by: Buzzy \nSigned-off-by: Jonathan Cameron \nCc: \n---\n hw/mem/cxl_type3.c | 4 ++++\n hw/pci-bridge/cxl_upstream.c | 4 ++++\n 2 files changed, 8 insertions(+)","diff":"diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c\nindex 4739239da3c5..763b6a024403 100644\n--- a/hw/mem/cxl_type3.c\n+++ b/hw/mem/cxl_type3.c\n@@ -278,6 +278,10 @@ static bool cxl_doe_cdat_rsp(DOECap *doe_cap)\n }\n \n ent = req->entry_handle;\n+ if (ent >= cdat->entry_len) {\n+ return false;\n+ }\n+\n base = cdat->entry[ent].base;\n len = cdat->entry[ent].length;\n \ndiff --git a/hw/pci-bridge/cxl_upstream.c b/hw/pci-bridge/cxl_upstream.c\nindex b6281cbd4cb0..fa53fa2777fd 100644\n--- a/hw/pci-bridge/cxl_upstream.c\n+++ b/hw/pci-bridge/cxl_upstream.c\n@@ -158,6 +158,10 @@ static bool cxl_doe_cdat_rsp(DOECap *doe_cap)\n }\n \n ent = req->entry_handle;\n+ if (ent >= cdat->entry_len) {\n+ return false;\n+ }\n+\n base = cdat->entry[ent].base;\n len = cdat->entry[ent].length;\n \n","prefixes":["qemu"]}