From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0F1143CEF7 for ; Thu, 30 Jul 2026 14:15:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785420916; cv=none; b=qbCHJpvERUZxuwJ0QvM+9pnmo+vQtQ2kEdLSdRnZK0d9Tlpw77WFdzgneQ6a7Dj9DSgYmLmp6laYaH10f1VDWfOhaBy3vUwVDV39Hj8R7Uv00SEG4Gu/Oy3dIoxfov6q9QL7t+MooXdQZuDddXDCT883cntwU62/AUE1zxWWoRw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785420916; c=relaxed/simple; bh=CRPst8b/oeCoOHTEjsNKGPjV+jufO/vwce3+80AFgNA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tiODRcBwtheyRl6R0s0/eJtwJ7CFejx7aKaJY558d9yZYYEWXsChjzbdgHFYUysoOQH+C8k0Yd/dXOKZ3aJgqdrSURpfIMNiCzpEq55kxzpdHHds9DMmvHTva89W81yVwUSJgqhXopTYaR/LJ69AuA8IIQfb9sgESlAev3ODKNU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=MqpdjvjA; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="MqpdjvjA" Received: from pps.filterd (m0360083.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 66UDHcEv3091316 for ; Thu, 30 Jul 2026 14:15:14 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=UYtSd+uK2nAmL8gwU Zv459FttMhsOiSRuzqM3DCHdDA=; b=MqpdjvjAO5uBt6EIx+813bFqZRCaVZwCA BBG8lV+QU4K382wa1y3BgfaheXTWqAGw4kIA9B2Q2MN/EVMVmBYhBJR2AFyguGIi 1M966PbD1Q+n0OPy72fXD552DllKvO8bOBFTDwfxWlhc/xo6K/D5jURE4UxfuM+F yRw091g1WtHkM7lI4F2Lc6bZlTH3CUY9YH11XavQOuogAAzmyzGPDsRgfXOrT279 FeLl9V2KVNPo47hpq3zQJNTBY6Pt+MdNFJSANkGP2i7KcFJwwiE3l5wLliRd4Z8C qS8+eQ+hbF1U/zFTZv1NBew0XbyHA6n5Ze1721H0tWcJXT9NH9opg== Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4fmuw7r5kc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 30 Jul 2026 14:15:14 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 66UEBJaY015868 for ; Thu, 30 Jul 2026 14:15:13 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4fn7uwbu48-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 30 Jul 2026 14:15:12 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 66UEF8qF17433066 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Jul 2026 14:15:08 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B512120043; Thu, 30 Jul 2026 14:15:08 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 942462004E; Thu, 30 Jul 2026 14:15:08 +0000 (GMT) Received: from funtu2.ibm.com (unknown [9.111.145.36]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 30 Jul 2026 14:15:08 +0000 (GMT) From: Harald Freudenberger To: dengler@linux.ibm.com, fcallies@linux.ibm.com, ifranzki@linux.ibm.com Cc: freude@linux.ibm.com, linux-s390@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev Subject: [PATCH v10 2/5] s390/zcrypt: Improve CCA CPRB length and overflow checks Date: Thu, 30 Jul 2026 16:15:06 +0200 Message-ID: <20260730141509.205970-3-freude@linux.ibm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260730141509.205970-1-freude@linux.ibm.com> References: <20260730141509.205970-1-freude@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: rTel083GA6eO8t4nxNc54GUaOkyeYvN5 X-Proofpoint-ORIG-GUID: rTel083GA6eO8t4nxNc54GUaOkyeYvN5 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzMwMDEwNSBTYWx0ZWRfXx1UE7LFo33ZX YbCCxt3WGW9nQCv+jP9CzwlnSH7oc3DkomhDC7ff3udcRy1jW1vtdWYwpXHS/TDVIdue4rDbEuR zHEQ+3zOJ1niPvLZWzVrtO8Q5OCUdHnD5WEbA/0kmVVIUcFwntfwPHB+9XBInvkHoOeFs0wZulC 0/aHNwP3vl6LoW+FpQYa5thoj8U53dHVGbHItuqlW3tByEIG4I43GhwzUmUdMqcLlbyk8WtQUCA Q8M6jPAnBjrC0lnWflLmexvEv5XGmgYWLR43evYJnczroSTd/mMZhd/bz3tI/OLMTuvjmGWoY9Y qf16zaJTK3Nib2/GVpvuwPLwpcrJoPYcuZff9syMCLLbSeUVEKqX9EUydiCNmIopQ6c0Y/1+mql o5ysS+dMOiB6SgBXGZpTR6GSu9CZ90Q3IgbmWvnzDc1ky1TItE6fViRLHQLkYxq36PfvKNQWgKh r1TaS3xYzSaOhVyM8pg== X-Authority-Analysis: v=2.4 cv=SKFykuvH c=1 sm=1 tr=0 ts=6a6b5c72 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=VnNF1IyMAAAA:8 a=VwQbUJbxAAAA:8 a=A9_4VoiraDeQe4jIP7EA:9 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzMwMDEwNSBTYWx0ZWRfXy21uya2W2WOE Qug1MgFZxkbFa67XKxBwlp6x6aRxwdHk9N+75K/G2W7r+OFGuD6KCXmvobgmcmp0V9OMfbnBBgj 6d8qS2+Z1d1i0fVAKStC5ntzQkHzOhY= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-30_04,2026-07-29_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 clxscore=1015 adultscore=0 lowpriorityscore=0 bulkscore=0 impostorscore=0 phishscore=0 spamscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607300105 The xcrb_msg_to_type6cprb_msgx() function lacks proper input validation, creating security vulnerabilities: 1. Integer overflow after CEIL4 alignment: Signed int variables could overflow during 4-byte boundary alignment, causing undersized buffer allocations or incorrect bounds checking. 2. Missing minimum size validation: The CPRBX structure is copied from userspace without verifying sufficient buffer length. Undersized buffers cause uninitialized memory access when reading structure fields like cprbx.cprb_len and cprbx.domain. 3. Arithmetic overflow in sum calculations: Adding control block and data block sizes could overflow, bypassing size checks and enabling buffer overflows. Fix by using size_t for length calculations, adding U32_MAX boundary checks after alignment, validating minimum control block size before copying from userspace, and detecting sum calculation overflows. Fixes: e2c6d91eb8b1 ("s390/zcrypt: Rework domain processing within zcrypt device driver") Signed-off-by: Harald Freudenberger Cc: stable@vger.kernel.org # 7.1+ --- drivers/s390/crypto/zcrypt_msgtype6.c | 78 +++++++++++++-------------- 1 file changed, 36 insertions(+), 42 deletions(-) diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c index 40f72cdf284d..fb37e28c8242 100644 --- a/drivers/s390/crypto/zcrypt_msgtype6.c +++ b/drivers/s390/crypto/zcrypt_msgtype6.c @@ -342,49 +342,40 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg, }; } __packed * msg = ap_msg->msg; - int rcblen = CEIL4(xcrb->request_control_blk_length); - int req_sumlen, resp_sumlen; - char *req_data = ap_msg->msg + sizeof(struct type6_hdr) + rcblen; - char *function_code; + size_t req_cblen, rep_cblen, req_sumlen, rep_sumlen; + char *function_code, *req_data; - if (CEIL4(xcrb->request_control_blk_length) < - xcrb->request_control_blk_length) - return -EINVAL; /* overflow after alignment*/ - - /* length checks */ + /* request length and overflow checks */ + if (xcrb->request_control_blk_length < sizeof(struct CPRBX)) + return -EINVAL; + req_cblen = CEIL4((size_t)xcrb->request_control_blk_length); + if (req_cblen > U32_MAX) + return -EINVAL; ap_msg->len = sizeof(struct type6_hdr) + - CEIL4(xcrb->request_control_blk_length) + - xcrb->request_data_length; + req_cblen + xcrb->request_data_length; if (ap_msg->len > ap_msg->bufsize) return -EINVAL; - - /* - * Overflow check - * sum must be greater (or equal) than the largest operand - */ - req_sumlen = CEIL4(xcrb->request_control_blk_length) + - xcrb->request_data_length; - if ((CEIL4(xcrb->request_control_blk_length) <= - xcrb->request_data_length) ? + req_sumlen = req_cblen + xcrb->request_data_length; + if (req_sumlen > U32_MAX) + return -EINVAL; + if (req_cblen <= xcrb->request_data_length ? req_sumlen < xcrb->request_data_length : - req_sumlen < CEIL4(xcrb->request_control_blk_length)) { + req_sumlen < req_cblen) { return -EINVAL; } - if (CEIL4(xcrb->reply_control_blk_length) < - xcrb->reply_control_blk_length) - return -EINVAL; /* overflow after alignment*/ - - /* - * Overflow check - * sum must be greater (or equal) than the largest operand - */ - resp_sumlen = CEIL4(xcrb->reply_control_blk_length) + - xcrb->reply_data_length; - if ((CEIL4(xcrb->reply_control_blk_length) <= - xcrb->reply_data_length) ? - resp_sumlen < xcrb->reply_data_length : - resp_sumlen < CEIL4(xcrb->reply_control_blk_length)) { + /* reply length and overflow checks */ + if (xcrb->reply_control_blk_length < sizeof(struct CPRBX)) + return -EINVAL; + rep_cblen = CEIL4((size_t)xcrb->reply_control_blk_length); + if (rep_cblen > U32_MAX) + return -EINVAL; + rep_sumlen = rep_cblen + xcrb->reply_data_length; + if (rep_sumlen > U32_MAX) + return -EINVAL; + if (rep_cblen <= xcrb->reply_data_length ? + rep_sumlen < xcrb->reply_data_length : + rep_sumlen < rep_cblen) { return -EINVAL; } @@ -393,7 +384,7 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg, memcpy(msg->hdr.agent_id, &xcrb->agent_ID, sizeof(xcrb->agent_ID)); msg->hdr.tocardlen1 = xcrb->request_control_blk_length; if (xcrb->request_data_length) { - msg->hdr.offset2 = msg->hdr.offset1 + rcblen; + msg->hdr.offset2 = msg->hdr.offset1 + req_cblen; msg->hdr.tocardlen2 = xcrb->request_data_length; } msg->hdr.fromcardlen1 = xcrb->reply_control_blk_length; @@ -404,8 +395,8 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg, xcrb->request_control_blk_addr, xcrb->request_control_blk_length)) return -EFAULT; - if (msg->cprbx.cprb_len + sizeof(msg->hdr.function_code) > - xcrb->request_control_blk_length) + /* copy subfunction code into AP msg type 6 function code field */ + if (msg->cprbx.cprb_len > req_cblen - sizeof(msg->hdr.function_code)) return -EINVAL; function_code = ((unsigned char *)&msg->cprbx) + msg->cprbx.cprb_len; memcpy(msg->hdr.function_code, function_code, @@ -437,10 +428,13 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg, } /* copy data block */ - if (xcrb->request_data_length && - z_copy_from_user(userspace, req_data, xcrb->request_data_address, - xcrb->request_data_length)) - return -EFAULT; + if (xcrb->request_data_length) { + req_data = ap_msg->msg + sizeof(struct type6_hdr) + req_cblen; + if (z_copy_from_user(userspace, req_data, + xcrb->request_data_address, + xcrb->request_data_length)) + return -EFAULT; + } return 0; } -- 2.43.0