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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 BE1F9C5DF61 for ; Thu, 7 Nov 2019 12:45:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8369E2187F for ; Thu, 7 Nov 2019 12:45:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388705AbfKGMpy (ORCPT ); Thu, 7 Nov 2019 07:45:54 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:26012 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733122AbfKGMpy (ORCPT ); Thu, 7 Nov 2019 07:45:54 -0500 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xA7CjS5K046113 for ; Thu, 7 Nov 2019 07:45:52 -0500 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w41w70fcp-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 07 Nov 2019 07:45:47 -0500 Received: from localhost by e06smtp02.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) Thu, 7 Nov 2019 12:44:13 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xA7CiBSk51708100 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 7 Nov 2019 12:44:11 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C09384C044; Thu, 7 Nov 2019 12:44:11 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 752CE4C058; Thu, 7 Nov 2019 12:44:11 +0000 (GMT) Received: from oc7455500831.ibm.com (unknown [9.152.224.123]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 7 Nov 2019 12:44:11 +0000 (GMT) Subject: Re: [PATCH v2] s390/pkey: Use memdup_user() rather than duplicating its implementation To: Markus Elfring , linux-s390@vger.kernel.org, Joe Perches , Harald Freudenberger , Heiko Carstens , Ingo Franzki , Vasily Gorbik Cc: LKML , kernel-janitors@vger.kernel.org References: <08422b7e-2071-ee52-049e-c3ac55bc67a9@web.de> <6137855bb4170c438c7436cbdb7dfd21639a8855.camel@perches.com> From: Christian Borntraeger Autocrypt: addr=borntraeger@de.ibm.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19110712-0008-0000-0000-0000032C6792 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19110712-0009-0000-0000-00004A4B6C88 Message-Id: <833d7d5e-6ede-6bdd-a2cc-2da7f0b03908@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-07_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911070128 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07.11.19 11:06, Markus Elfring wrote: > From: Markus Elfring > Date: Thu, 7 Nov 2019 10:40:18 +0100 > > Reuse existing functionality from memdup_user() instead of keeping > duplicate source code. > > Generated by: scripts/coccinelle/api/memdup_user.cocci > > Delete local variables which became unnecessary with this refactoring > in two function implementations. > > Fixes: f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d ("s390/pkey: add CCA AES cipher key support") With that patch description, the Fixes tag is wrong...but (see below) > Signed-off-by: Markus Elfring > --- > > v2: > Further changes were requested by Joe Perches. > https://lore.kernel.org/r/6137855bb4170c438c7436cbdb7dfd21639a8855.camel@perches.com/ > > * The proposed usage of two conditional operators was replaced by > an other code structure. > > * A sanity check was adjusted for the function “_copy_apqns_from_user”. > > > drivers/s390/crypto/pkey_api.c | 26 ++++---------------------- > 1 file changed, 4 insertions(+), 22 deletions(-) > > diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c > index 9de3d46b3253..ac99fd97569d 100644 > --- a/drivers/s390/crypto/pkey_api.c > +++ b/drivers/s390/crypto/pkey_api.c > @@ -715,36 +715,18 @@ static int pkey_apqns4keytype(enum pkey_key_type ktype, > > static void *_copy_key_from_user(void __user *ukey, size_t keylen) > { > - void *kkey; > - > if (!ukey || keylen < MINKEYBLOBSIZE || keylen > KEYBLOBBUFSIZE) > return ERR_PTR(-EINVAL); > - kkey = kmalloc(keylen, GFP_KERNEL); > - if (!kkey) > - return ERR_PTR(-ENOMEM); > - if (copy_from_user(kkey, ukey, keylen)) { > - kfree(kkey); > - return ERR_PTR(-EFAULT); > - } > > - return kkey; > + return memdup_user(ukey, keylen); This part looks good > } > > static void *_copy_apqns_from_user(void __user *uapqns, size_t nr_apqns) > { This part below is not an equivalent replacement. In fact you are fixing a bug here... > - void *kapqns = NULL; > - size_t nbytes; > - > - if (uapqns && nr_apqns > 0) { > - nbytes = nr_apqns * sizeof(struct pkey_apqn); > - kapqns = kmalloc(nbytes, GFP_KERNEL); > - if (!kapqns) > - return ERR_PTR(-ENOMEM); > - if (copy_from_user(kapqns, uapqns, nbytes)) .... here we would need to kfree kapqns, but we do not. So this is a memory leak. Isnt it? So indeed this is fixing something. But please rework your the patch description accordingly. > - return ERR_PTR(-EFAULT); > - } > + if (!uapqns || nr_apqns <= 0) > + return NULL; > > - return kapqns; > + return memdup_user(uapqns, nr_apqns * sizeof(struct pkey_apqn)); > } > > static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, > -- > 2.24.0 >