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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6A931C48BC3 for ; Mon, 19 Feb 2024 22:18:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gIMTwEVPWgrhBul26LZ8ChMV6y8vqC4lyceqCWMp5uA=; b=35V0SiG8XVZf6I zAyu7SBBK1MiD64atHtKpudud7OW46j8trG+FmuxKRnikSzDT1H9xySJKuo3WLn6ImdPIpEB+Fmnl wW41V3DtzS/CE+ARBf9TS+YCH/XL3jeoFOl9Ybe8GmljmoXNlPagtAPd2ULlAMBXz9wPeXxz6v5nd sySQRwj1Fwkh2nOe9j+DhE0x4gkAzUP/gEXAjssptpbkFHreVe3QieqzEWxBcSACulB/mHFydGjtg cIIKp0iDsOKY/9eR19bX1gFNpC+uiNS0JF8pWOdC0xGuPQxZFg+Duby1pNsLkUkBy9F08Lud2gUAJ OeI7GXzdjQdpJjd1MJlg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rcBxm-0000000CMHt-16gX; Mon, 19 Feb 2024 22:18:14 +0000 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rcBxg-0000000CMDk-1IoQ for kexec@lists.infradead.org; Mon, 19 Feb 2024 22:18:13 +0000 Received: from pps.filterd (m0360083.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 41JM60of023284; Mon, 19 Feb 2024 22:17:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=m2vVnm3WIOYe8tuZvxVsO+fx9MrfXEx+Kc5KgrKSaic=; b=qpEiGoMwHmSAG+LlsDVzaIP8Z01j97qKKgXTCZnbv6Je+a4GbHJ+gcDsIH+iAasHe/d+ paFuvpalrHhVGXfxAUT45lKr5D+t7mePHqlHXCCKFjCGn1hDkRtMuDDhZplT2ZlCl69g 2ayTKNTuSQb3PhJuW1Uxiej8VYryFVRnys328SPm40Qt56xfKUX/C5RX9ag6hLK7Z3e1 WtPZzzYneefEecifJOItvaxyqfpdxKLYi5uLAgDR7JMchxpm0GvRUSi4ZSaBFoAReN6z MpwTFf+Iha336UsObxyEDMqyqhd3XhXmrr59WWxRAyVcJP3d3tqiGdviBTpn7tjBANJh 9Q== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3wce8n9wq3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Feb 2024 22:16:59 +0000 Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 41JJbDZt009540; Mon, 19 Feb 2024 22:16:58 GMT Received: from smtprelay02.wdc07v.mail.ibm.com ([172.16.1.69]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 3wb84p49m3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Feb 2024 22:16:58 +0000 Received: from smtpav02.dal12v.mail.ibm.com (smtpav02.dal12v.mail.ibm.com [10.241.53.101]) by smtprelay02.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 41JMGtDj9503450 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 19 Feb 2024 22:16:58 GMT Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 915535805E; Mon, 19 Feb 2024 22:16:55 +0000 (GMT) Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D58A458051; Mon, 19 Feb 2024 22:16:53 +0000 (GMT) Received: from [9.47.158.152] (unknown [9.47.158.152]) by smtpav02.dal12v.mail.ibm.com (Postfix) with ESMTP; Mon, 19 Feb 2024 22:16:53 +0000 (GMT) Message-ID: <6a2b6fee-6f3c-4099-983a-3be3ecd091b6@linux.ibm.com> Date: Mon, 19 Feb 2024 17:16:53 -0500 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 1/8] ima: define and call ima_alloc_kexec_file_buf Content-Language: en-US To: Tushar Sugandhi , zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com References: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> <20240214153827.1087657-2-tusharsu@linux.microsoft.com> From: Stefan Berger In-Reply-To: <20240214153827.1087657-2-tusharsu@linux.microsoft.com> X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 2sJIqJ5zuL-g3LV3CBhtMkpIcqOU_G81 X-Proofpoint-ORIG-GUID: 2sJIqJ5zuL-g3LV3CBhtMkpIcqOU_G81 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-02-19_20,2024-02-19_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 spamscore=0 mlxlogscore=999 clxscore=1015 adultscore=0 malwarescore=0 phishscore=0 priorityscore=1501 lowpriorityscore=0 mlxscore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2402190167 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240219_141808_400208_4F8FFC7C X-CRM114-Status: GOOD ( 39.62 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 2/14/24 10:38, Tushar Sugandhi wrote: > Carrying the IMA measurement list across kexec requires allocating a > buffer and copying the measurement records. Separate allocating the > buffer and copying the measurement records into separate functions in > order to allocate the buffer at kexec 'load' and copy the measurements > at kexec 'execute'. > > This patch includes the following changes: > - Refactor ima_dump_measurement_list() to move the memory allocation > to a separate function ima_alloc_kexec_file_buf() which allocates > buffer of size 'kexec_segment_size' at kexec 'load'. > - Make the local variable ima_kexec_file in ima_dump_measurement_list() > as local static to the file, so that it can be accessed from as -> a > ima_alloc_kexec_file_buf(). > - Make necessary changes to the function ima_add_kexec_buffer() to call > the above two functions. > > Suggested-by: Stefan Berger > Signed-off-by: Tushar Sugandhi > --- > security/integrity/ima/ima_kexec.c | 107 +++++++++++++++++++++-------- > 1 file changed, 78 insertions(+), 29 deletions(-) > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > index dadc1d138118..a9cb5e882e2e 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -15,62 +15,98 @@ > #include "ima.h" > > #ifdef CONFIG_IMA_KEXEC > +static struct seq_file ima_kexec_file; > + > +static void ima_reset_kexec_file(struct seq_file *sf) > +{ > + sf->buf = NULL; > + sf->size = 0; > + sf->read_pos = 0; > + sf->count = 0; > +} > + > +static void ima_free_kexec_file_buf(struct seq_file *sf) > +{ > + vfree(sf->buf); > + ima_reset_kexec_file(sf); > +} > + > +static int ima_alloc_kexec_file_buf(size_t segment_size) > +{ > + /* > + * kexec 'load' may be called multiple times. > + * Free and realloc the buffer only if the segment_size is > + * changed from the previous kexec 'load' call. > + */ > + if (ima_kexec_file.buf && > + ima_kexec_file.size == segment_size && > + ima_kexec_file.read_pos == 0 && > + ima_kexec_file.count == sizeof(struct ima_kexec_hdr)) > + return 0; > + > + ima_free_kexec_file_buf(&ima_kexec_file); > + > + /* segment size can't change between kexec load and execute */ > + ima_kexec_file.buf = vmalloc(segment_size); > + if (!ima_kexec_file.buf) > + return -ENOMEM; > + > + ima_kexec_file.size = segment_size; > + ima_kexec_file.read_pos = 0; > + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > + > + return 0; > +} > + > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > unsigned long segment_size) > { > struct ima_queue_entry *qe; > - struct seq_file file; > struct ima_kexec_hdr khdr; > - int ret = 0; > > - /* segment size can't change between kexec load and execute */ > - file.buf = vmalloc(segment_size); > - if (!file.buf) { > - ret = -ENOMEM; > - goto out; > + if (!ima_kexec_file.buf) { > + *buffer_size = 0; > + *buffer = NULL; If you return -EINVAL then the caller should not look at the buffer but at 'ret' (5/8). So I don't think it's necessary to initialize these variables since the caller shouldn't look at them. > + pr_err("%s: Kexec file buf not allocated\n", __func__); > + return -EINVAL; > } > > - file.size = segment_size; > - file.read_pos = 0; > - file.count = sizeof(khdr); /* reserved space */ > - > memset(&khdr, 0, sizeof(khdr)); > khdr.version = 1; > + > + /* Copy as many IMA measurements list records as possible */ > list_for_each_entry_rcu(qe, &ima_measurements, later) { > - if (file.count < file.size) { > + if (ima_kexec_file.count < ima_kexec_file.size) { > khdr.count++; > - ima_measurements_show(&file, qe); > + ima_measurements_show(&ima_kexec_file, qe); > } else { > - ret = -EINVAL; > + pr_err("%s: IMA log file is too big for Kexec buf\n", > + __func__); > break; > } > } > > - if (ret < 0) > - goto out; > - > /* > * fill in reserved space with some buffer details > * (eg. version, buffer size, number of measurements) > */ > - khdr.buffer_size = file.count; > + khdr.buffer_size = ima_kexec_file.count; > if (ima_canonical_fmt) { > khdr.version = cpu_to_le16(khdr.version); > khdr.count = cpu_to_le64(khdr.count); > khdr.buffer_size = cpu_to_le64(khdr.buffer_size); > } > - memcpy(file.buf, &khdr, sizeof(khdr)); > + memcpy(ima_kexec_file.buf, &khdr, sizeof(khdr)); > > print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1, > - file.buf, file.count < 100 ? file.count : 100, > + ima_kexec_file.buf, ima_kexec_file.count < 100 ? > + ima_kexec_file.count : 100, > true); > > - *buffer_size = file.count; > - *buffer = file.buf; > -out: > - if (ret == -EINVAL) > - vfree(file.buf); > - return ret; > + *buffer_size = ima_kexec_file.count; > + *buffer = ima_kexec_file.buf; > + > + return 0; > } > > /* > @@ -108,13 +144,20 @@ void ima_add_kexec_buffer(struct kimage *image) > return; > } > > - ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, > - kexec_segment_size); > - if (!kexec_buffer) { > + ret = ima_alloc_kexec_file_buf(kexec_segment_size); > + if (ret < 0) { > pr_err("Not enough memory for the kexec measurement buffer.\n"); > return; > } > > + ret = ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, > + kexec_segment_size); > + if (ret < 0) { > + pr_err("%s: Failed to dump IMA measurements. Error:%d.\n", > + __func__, ret); > + return; > + } > + > kbuf.buffer = kexec_buffer; > kbuf.bufsz = kexec_buffer_size; > kbuf.memsz = kexec_segment_size; > @@ -129,6 +172,12 @@ void ima_add_kexec_buffer(struct kimage *image) > image->ima_buffer_size = kexec_segment_size; > image->ima_buffer = kexec_buffer; > > + /* > + * kexec owns kexec_buffer after kexec_add_buffer() is called > + * and it will vfree() that buffer. > + */ Actually, that's not quite right what I told you. "kexec owns kexec_buffer due to ima->ima_buffer and it will vfree() this buffer." > + ima_reset_kexec_file(&ima_kexec_file); > + > kexec_dprintk("kexec measurement buffer for the loaded kernel at 0x%lx.\n", > kbuf.mem); > } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec