From patchwork Mon Mar 22 15:42:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 12155141 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D7E21C433E1 for ; Mon, 22 Mar 2021 15:43:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B28F2619A8 for ; Mon, 22 Mar 2021 15:43:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230084AbhCVPnK (ORCPT ); Mon, 22 Mar 2021 11:43:10 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35308 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230034AbhCVPmk (ORCPT ); Mon, 22 Mar 2021 11:42:40 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12MFYCQb050623; Mon, 22 Mar 2021 11:42:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=JSGjVlSecphP6Rjd5Yu8JmkAMUWPNySTAdpd2p4Iy40=; b=WmG9LedD/nB60DmtYU1RcobF8drhFu6Vo3N/rpDEGJnVTpR4NgTtYq/sxCfJdqds+9zZ D4hLG168AupmirTihXJOQ9J55IJKEfw7SbpdhSB7qEjYslImm7sQaYFvQN0vWuhbRX+q Ylqaf31ncJPeuJMw1yd6ENd5dW33jm8g6BDy9TLt9iYJ4CGo40Wj6bfczvVOZZImoOM/ IChgSY6cFG3kfTqxi/d8N7lkl6GdQYJ+At9BD/riXk2hicCpRHOf8TX0ttU5b+7D3oU+ soJKUsrv7eJoiXoEylJ2Q5j50tJFa6qawOrXRiJUk2Ydjpwg25Dsx57c8sN5+SpdLsA4 UQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 37dwy5nede-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 11:42:30 -0400 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 12MFai07061716; Mon, 22 Mar 2021 11:42:29 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 37dwy5nebs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 11:42:29 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 12MFdP38005787; Mon, 22 Mar 2021 15:42:27 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma04ams.nl.ibm.com with ESMTP id 37d99rag6u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 15:42:27 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 12MFgPDM40567134 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 22 Mar 2021 15:42:25 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E1EC24C046; Mon, 22 Mar 2021 15:42:24 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 718874C052; Mon, 22 Mar 2021 15:42:22 +0000 (GMT) Received: from li-f45666cc-3089-11b2-a85c-c57d1a57929f.ibm.com.ibmuc.com (unknown [9.211.152.56]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 22 Mar 2021 15:42:22 +0000 (GMT) From: Mimi Zohar To: Dmitry Vyukov Cc: Mimi Zohar , James Morris , "Serge E . Hallyn" , linux-integrity@vger.kernel.org, linux-security-module , LKML , Eric Biggers , Kees Cook Subject: [PATCH 1/2] ima: don't access a file's integrity status before an IMA policy is loaded Date: Mon, 22 Mar 2021 11:42:06 -0400 Message-Id: <20210322154207.6802-1-zohar@linux.ibm.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-22_08:2021-03-22,2021-03-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 bulkscore=0 mlxscore=0 suspectscore=0 clxscore=1015 phishscore=0 impostorscore=0 mlxlogscore=999 malwarescore=0 adultscore=0 priorityscore=1501 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103220111 Precedence: bulk List-ID: Only after an IMA policy is loaded, check, save, or update the cached file's integrity status. Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 9ef748ea829f..9d1196f712e1 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -606,6 +606,9 @@ void ima_post_create_tmpfile(struct user_namespace *mnt_userns, struct integrity_iint_cache *iint; int must_appraise; + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, FILE_CHECK); if (!must_appraise) @@ -636,6 +639,9 @@ void ima_post_path_mknod(struct user_namespace *mnt_userns, struct inode *inode = dentry->d_inode; int must_appraise; + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, FILE_CHECK); if (!must_appraise) From patchwork Mon Mar 22 15:42:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 12155143 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B4C03C433E0 for ; Mon, 22 Mar 2021 15:43:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9301061606 for ; Mon, 22 Mar 2021 15:43:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230203AbhCVPnL (ORCPT ); Mon, 22 Mar 2021 11:43:11 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39466 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230340AbhCVPmq (ORCPT ); Mon, 22 Mar 2021 11:42:46 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12MFXJkO087703; Mon, 22 Mar 2021 11:42:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=Be/8jzfNAsAOvRtIz1Gjl8IbLBAyHccy2qh9qtGmq6Y=; b=HJtNAlJxQ4hPgwpJYlupyaszhvX8L1z0opXunLxgeRxaEETsVBgQ5bVrrghmb0JxTFWv L3xr5tMhADnTsUo55SbBzlT+vN4NV0NMhHq6uPj9bFW8fdpVlw4KJwyVdA8GJf620jwj +73Vmly/kDMHlJJbBVDC5DnsyIUde8JX1O5Z+Ndt8IN8+KO+gcO/p8DR0bO+C9tVQxyb XHmEXV6ta2PujUVNye2tqwrYcZvY3cMDNqKp/N3ikPf0IfbMxt7RW2tf8LFvW9BdMZJT wEKRA3dNKtyfJJCSsqpZL2X63SzAoDzezfyo1jg3AhNRkug61jZnWzIV5NxNvlOzvkBz NA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 37eb1pha7h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 11:42:36 -0400 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 12MFXqiO089234; Mon, 22 Mar 2021 11:42:35 -0400 Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 37eb1pha6v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 11:42:35 -0400 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 12MFdDU0015798; Mon, 22 Mar 2021 15:42:34 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma03fra.de.ibm.com with ESMTP id 37d9bps9sn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Mar 2021 15:42:33 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 12MFgV4w11272578 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 22 Mar 2021 15:42:31 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A3C1F4C046; Mon, 22 Mar 2021 15:42:31 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 65B034C044; Mon, 22 Mar 2021 15:42:29 +0000 (GMT) Received: from li-f45666cc-3089-11b2-a85c-c57d1a57929f.ibm.com.ibmuc.com (unknown [9.211.152.56]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 22 Mar 2021 15:42:29 +0000 (GMT) From: Mimi Zohar To: Dmitry Vyukov Cc: Mimi Zohar , James Morris , "Serge E . Hallyn" , linux-integrity@vger.kernel.org, linux-security-module , LKML , Eric Biggers , Kees Cook Subject: [PATCH 2/2] integrity: double check iint_cache was initialized Date: Mon, 22 Mar 2021 11:42:07 -0400 Message-Id: <20210322154207.6802-2-zohar@linux.ibm.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210322154207.6802-1-zohar@linux.ibm.com> References: <20210322154207.6802-1-zohar@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-22_07:2021-03-22,2021-03-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxlogscore=834 lowpriorityscore=0 clxscore=1015 priorityscore=1501 phishscore=0 spamscore=0 adultscore=0 malwarescore=0 suspectscore=0 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103220111 Precedence: bulk List-ID: The kernel may be built with multiple LSMs, but only a subset may be enabled on the boot command line by specifying "lsm=". Not including "integrity" on the ordered LSM list may result in a NULL deref. As reported by Dmitry Vyukov: in qemu: qemu-system-x86_64 -enable-kvm -machine q35,nvdimm -cpu max,migratable=off -smp 4 -m 4G,slots=4,maxmem=16G -hda wheezy.img -kernel arch/x86/boot/bzImage -nographic -vga std -soundhw all -usb -usbdevice tablet -bt hci -bt device:keyboard -net user,host=10.0.2.10,hostfwd=tcp::10022-:22 -net nic,model=virtio-net-pci -object memory-backend-file,id=pmem1,share=off,mem-path=/dev/zero,size=64M -device nvdimm,id=nvdimm1,memdev=pmem1 -append "console=ttyS0 root=/dev/sda earlyprintk=serial rodata=n oops=panic panic_on_warn=1 panic=86400 lsm=smack numa=fake=2 nopcid dummy_hcd.num=8" -pidfile vm_pid -m 2G -cpu host But it crashes on NULL deref in integrity_inode_get during boot: Run /sbin/init as init process BUG: kernel NULL pointer dereference, address: 000000000000001c PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc2+ #97 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-44-g88ab0c15525c-prebuilt.qemu.org 04/01/2014 RIP: 0010:kmem_cache_alloc+0x2b/0x370 mm/slub.c:2920 Code: 57 41 56 41 55 41 54 41 89 f4 55 48 89 fd 53 48 83 ec 10 44 8b 3d d9 1f 90 0b 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 31 c0 <8b> 5f 1c 4cf RSP: 0000:ffffc9000032f9d8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888017fc4f00 RCX: 0000000000000000 RDX: ffff888040220000 RSI: 0000000000000c40 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888019263627 R10: ffffffff83937cd1 R11: 0000000000000000 R12: 0000000000000c40 R13: ffff888019263538 R14: 0000000000000000 R15: 0000000000ffffff FS: 0000000000000000(0000) GS:ffff88802d180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000001c CR3: 000000000b48e000 CR4: 0000000000750ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: integrity_inode_get+0x47/0x260 security/integrity/iint.c:105 process_measurement+0x33d/0x17e0 security/integrity/ima/ima_main.c:237 ima_bprm_check+0xde/0x210 security/integrity/ima/ima_main.c:474 security_bprm_check+0x7d/0xa0 security/security.c:845 search_binary_handler fs/exec.c:1708 [inline] exec_binprm fs/exec.c:1761 [inline] bprm_execve fs/exec.c:1830 [inline] bprm_execve+0x764/0x19a0 fs/exec.c:1792 kernel_execve+0x370/0x460 fs/exec.c:1973 try_to_run_init_process+0x14/0x4e init/main.c:1366 kernel_init+0x11d/0x1b8 init/main.c:1477 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: CR2: 000000000000001c ---[ end trace 22d601a500de7d79 ]--- Since LSMs and IMA may be configured at build time, but not enabled at run time, panic the system if "integrity" was not initialized before use. Reported-by: Dmitry Vyukov Fixes: 79f7865d844c ("LSM: Introduce "lsm=" for boottime LSM selection") Signed-off-by: Mimi Zohar --- security/integrity/iint.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 1d20003243c3..0ba01847e836 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -98,6 +98,14 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode) struct rb_node *node, *parent = NULL; struct integrity_iint_cache *iint, *test_iint; + /* + * The integrity's "iint_cache" is initialized at security_init(), + * unless it is not included in the ordered list of LSMs enabled + * on the boot command line. + */ + if (!iint_cache) + panic("%s: lsm=integrity required.\n", __func__); + iint = integrity_iint_find(inode); if (iint) return iint;