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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 A85D3C43381 for ; Tue, 26 Mar 2019 15:29:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8045920823 for ; Tue, 26 Mar 2019 15:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731535AbfCZP3j (ORCPT ); Tue, 26 Mar 2019 11:29:39 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33080 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731546AbfCZP3h (ORCPT ); Tue, 26 Mar 2019 11:29:37 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2QFP9Fg124879 for ; Tue, 26 Mar 2019 11:29:36 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rfp0qb4be-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 26 Mar 2019 11:29:35 -0400 Received: from localhost by e06smtp07.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) Tue, 26 Mar 2019 15:29:30 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2QFTT1A50004134 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 26 Mar 2019 15:29:29 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 61EC4AE053; Tue, 26 Mar 2019 15:29:29 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E9D5EAE045; Tue, 26 Mar 2019 15:29:27 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.109.36]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 26 Mar 2019 15:29:27 +0000 (GMT) Subject: Re: [PATCH ghak109 V1] audit: link integrity evm_write_xattrs record to syscall event From: Mimi Zohar To: Steve Grubb , Richard Guy Briggs Cc: Paul Moore , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, Linux-Audit Mailing List , LKML , omosnace@redhat.com, Eric Paris , Serge Hallyn , mjg59@google.com Date: Tue, 26 Mar 2019 11:29:17 -0400 In-Reply-To: <2006016.NXIvICiRTL@x2> References: <81d0122d14c4fbb3a2ad33d25fdf2dd001c7dcc7.1552737854.git.rgb@redhat.com> <20190321005008.wfz3bk7q262km5fz@madcap2.tricolour.ca> <2006016.NXIvICiRTL@x2> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19032615-0028-0000-0000-00000358810E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19032615-0029-0000-0000-000024173979 Message-Id: <1553614157.4115.17.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-26_11:,, 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=8.0.1-1810050000 definitions=main-1903260107 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, 2019-03-26 at 11:22 -0400, Steve Grubb wrote: > > > > --- a/security/integrity/evm/evm_secfs.c > > > > +++ b/security/integrity/evm/evm_secfs.c > > > > @@ -192,7 +192,8 @@ static ssize_t evm_write_xattrs(struct file *file, > > > > const char __user *buf,> > > > > > if (count > XATTR_NAME_MAX) > > > > > > > > return -E2BIG; > > > > > > > > - ab = audit_log_start(NULL, GFP_KERNEL, > > > > AUDIT_INTEGRITY_EVM_XATTR); > > > > + ab = audit_log_start(audit_context(), GFP_KERNEL, > > > > + AUDIT_INTEGRITY_EVM_XATTR); > > > > > > This part is fine. > > > > > > > if (!ab) > > > > > > > > return -ENOMEM; > > > > > > > > @@ -222,7 +223,7 @@ static ssize_t evm_write_xattrs(struct file *file, > > > > const char __user *buf,> > > > > > inode_lock(inode); > > > > err = simple_setattr(evm_xattrs, &newattrs); > > > > inode_unlock(inode); > > > > > > > > - audit_log_format(ab, "locked"); > > > > + audit_log_format(ab, "xattr=(locked)"); > > > > > > Two things come to mind: > > > > > > * While we can clearly trust the string above, should we be logging > > > the xattr field value as an untrusted string so it is consistent with > > > how we record other xattr names? > > > > That would be a question for Steve. > > All fields with the same name must be represented the same way. If one > instance is untrusted, every instance of the same keyword must be untrusted. Normal case: audit_log_format(ab, "xattr="); audit_log_untrustedstring(ab, xattr->name); Ok, so the above audit_log_format() call should be replaced with  audit_log_untrustedstring(). Mimi