From patchwork Tue Mar 27 13:57:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Berger X-Patchwork-Id: 10310121 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 729E3600F6 for ; Tue, 27 Mar 2018 13:57:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 58BAA25E13 for ; Tue, 27 Mar 2018 13:57:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4AE9E26419; Tue, 27 Mar 2018 13:57:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A095A298DA for ; Tue, 27 Mar 2018 13:57:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752275AbeC0N5a (ORCPT ); Tue, 27 Mar 2018 09:57:30 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44202 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752803AbeC0N52 (ORCPT ); Tue, 27 Mar 2018 09:57:28 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w2RDtulw017505 for ; Tue, 27 Mar 2018 09:57:27 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2gyn2fqa8q-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Tue, 27 Mar 2018 09:57:27 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 27 Mar 2018 09:57:22 -0400 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w2RDvMU049741906; Tue, 27 Mar 2018 13:57:22 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1F13CB2050; Tue, 27 Mar 2018 10:59:32 -0400 (EDT) Received: from sbct-3.watson.ibm.com (unknown [9.47.158.153]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP id 04D72B2052; Tue, 27 Mar 2018 10:59:32 -0400 (EDT) From: Stefan Berger To: linux-integrity@vger.kernel.org Cc: containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, tycho@docker.com, serge@hallyn.com, sunyuqiong1988@gmail.com, david.safford@ge.com, mkayaalp@cs.binghamton.edu, James.Bottomley@HansenPartnership.com, zohar@linux.vnet.ibm.com, ebiederm@xmission.com, Mehmet Kayaalp Subject: [RFC PATCH v3 2/3] ima: Add ns_status for storing namespaced iint data Date: Tue, 27 Mar 2018 09:57:17 -0400 X-Mailer: git-send-email 2.5.5 In-Reply-To: <1522159038-14175-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1522159038-14175-1-git-send-email-stefanb@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18032713-0036-0000-0000-000002D6C82B X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008753; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000255; SDB=6.01009167; UDB=6.00514062; IPR=6.00788449; MB=3.00020268; MTD=3.00000008; XFM=3.00000015; UTC=2018-03-27 13:57:25 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18032713-0037-0000-0000-000043C73AD7 Message-Id: <1522159038-14175-3-git-send-email-stefanb@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-03-27_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803270141 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Mehmet Kayaalp This patch adds an rbtree to the IMA namespace structure that stores a namespaced version of iint->flags in ns_status struct. Similar to the integrity_iint_cache, both the iint ns_struct are looked up using the inode pointer value. The lookup, allocate, and insertion code is also similar, except ns_struct is not free'd when the inode is free'd. Instead, the lookup verifies the i_ino and i_generation fields are also a match. This could be replaced by a lazy clean up of the rbtree. Signed-off-by: Mehmet Kayaalp Changelog: v2: * fixed tree traversal in __ima_ns_status_find() --- include/linux/ima.h | 3 + security/integrity/ima/ima.h | 19 +++++ security/integrity/ima/ima_init_ima_ns.c | 6 ++ security/integrity/ima/ima_ns.c | 117 +++++++++++++++++++++++++++++++ 4 files changed, 145 insertions(+) diff --git a/include/linux/ima.h b/include/linux/ima.h index 8bca67df0ad3..734934261011 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -110,6 +110,9 @@ static inline int ima_inode_removexattr(struct dentry *dentry, struct ima_namespace { struct kref kref; struct ima_namespace *parent; + struct rb_root ns_status_tree; + rwlock_t ns_status_lock; + struct kmem_cache *ns_status_cache; }; extern struct ima_namespace init_ima_ns; diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e98c11c7cf75..e51a39ff75ff 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -128,6 +128,14 @@ static inline void ima_load_kexec_buffer(void) {} */ extern bool ima_canonical_fmt; +struct ns_status { + struct rb_node rb_node; + struct inode *inode; + ino_t i_ino; + u32 i_generation; + unsigned long flags; +}; + /* Internal IMA function definitions */ int ima_init(void); int ima_fs_init(void); @@ -295,6 +303,17 @@ int ima_ns_init(void); struct ima_namespace; int ima_init_namespace(struct ima_namespace *ns); +#ifdef CONFIG_IMA_NS +struct ns_status *ima_get_ns_status(struct ima_namespace *ns, + struct inode *inode); +#else +static inline struct ns_status *ima_get_ns_status(struct ima_namespace *ns, + struct inode *inode) +{ + return NULL; +} +#endif /* CONFIG_IMA_NS */ + /* LSM based policy rules require audit */ #ifdef CONFIG_IMA_LSM_RULES diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c index 52cb94b1d392..66b681c1c722 100644 --- a/security/integrity/ima/ima_init_ima_ns.c +++ b/security/integrity/ima/ima_init_ima_ns.c @@ -12,9 +12,15 @@ #include #include #include +#include + +#include "ima.h" int ima_init_namespace(struct ima_namespace *ns) { + ns->ns_status_tree = RB_ROOT; + rwlock_init(&ns->ns_status_lock); + ns->ns_status_cache = KMEM_CACHE(ns_status, SLAB_PANIC); return 0; } diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c index 62148908015a..ef70fd1e25c6 100644 --- a/security/integrity/ima/ima_ns.c +++ b/security/integrity/ima/ima_ns.c @@ -69,9 +69,23 @@ struct ima_namespace *copy_ima(struct ima_namespace *old_ns) return new_ns; } +static void free_ns_status_cache(struct ima_namespace *ns) +{ + struct ns_status *status, *next; + + write_lock(&ns->ns_status_lock); + rbtree_postorder_for_each_entry_safe(status, next, + &ns->ns_status_tree, rb_node) + kmem_cache_free(ns->ns_status_cache, status); + ns->ns_status_tree = RB_ROOT; + write_unlock(&ns->ns_status_lock); + kmem_cache_destroy(ns->ns_status_cache); +} + static void destroy_ima_ns(struct ima_namespace *ns) { put_ima_ns(ns->parent); + free_ns_status_cache(ns); kfree(ns); } @@ -84,3 +98,106 @@ void free_ima_ns(struct kref *kref) destroy_ima_ns(ns); } + +/* + * __ima_ns_status_find - return the ns_status associated with an inode + */ +static struct ns_status *__ima_ns_status_find(struct ima_namespace *ns, + struct inode *inode) +{ + struct ns_status *status; + struct rb_node *n = ns->ns_status_tree.rb_node; + + while (n) { + status = rb_entry(n, struct ns_status, rb_node); + + if (inode < status->inode) + n = n->rb_left; + else if (inode > status->inode) + n = n->rb_right; + else + break; + } + if (!n) + return NULL; + + return status; +} + +/* + * ima_ns_status_find - return the ns_status associated with an inode + */ +static struct ns_status *ima_ns_status_find(struct ima_namespace *ns, + struct inode *inode) +{ + struct ns_status *status; + + read_lock(&ns->ns_status_lock); + status = __ima_ns_status_find(ns, inode); + read_unlock(&ns->ns_status_lock); + + return status; +} + +void insert_ns_status(struct ima_namespace *ns, struct inode *inode, + struct ns_status *status) +{ + struct rb_node **p; + struct rb_node *node, *parent = NULL; + struct ns_status *test_status; + + p = &ns->ns_status_tree.rb_node; + while (*p) { + parent = *p; + test_status = rb_entry(parent, struct ns_status, rb_node); + if (inode < test_status->inode) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + node = &status->rb_node; + rb_link_node(node, parent, p); + rb_insert_color(node, &ns->ns_status_tree); +} + +struct ns_status *ima_get_ns_status(struct ima_namespace *ns, + struct inode *inode) +{ + struct ns_status *status; + int skip_insert = 0; + + status = ima_ns_status_find(ns, inode); + if (status) { + /* + * Unlike integrity_iint_cache we are not free'ing the + * ns_status data when the inode is free'd. So, in addition to + * checking the inode pointer, we need to make sure the + * (i_generation, i_ino) pair matches as well. In the future + * we might want to add support for lazily walking the rbtree + * to clean it up. + */ + if (inode->i_ino == status->i_ino && + inode->i_generation == status->i_generation) + return status; + + /* Same inode number is reused, overwrite the ns_status */ + skip_insert = 1; + } else { + status = kmem_cache_alloc(ns->ns_status_cache, GFP_NOFS); + if (!status) + return ERR_PTR(-ENOMEM); + } + + write_lock(&ns->ns_status_lock); + + if (!skip_insert) + insert_ns_status(ns, inode, status); + + status->inode = inode; + status->i_ino = inode->i_ino; + status->i_generation = inode->i_generation; + status->flags = 0UL; + write_unlock(&ns->ns_status_lock); + + return status; +}