From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932626AbeCIUOw (ORCPT ); Fri, 9 Mar 2018 15:14:52 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:34752 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932377AbeCIUOn (ORCPT ); Fri, 9 Mar 2018 15:14:43 -0500 From: Stefan Berger To: linux-ima-devel@lists.sourceforge.net 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, linux-integrity@vger.kernel.org, James.Bottomley@HansenPartnership.com, zohar@linux.vnet.ibm.com, Mehmet Kayaalp Subject: [RFC PATCH v2 2/3] ima: Add ns_status for storing namespaced iint data Date: Fri, 9 Mar 2018 15:14:20 -0500 X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180309201421.6150-1-stefanb@linux.vnet.ibm.com> References: <20180309201421.6150-1-stefanb@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18030920-0048-0000-0000-00000247A6C8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008642; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.01000666; UDB=6.00509012; IPR=6.00779996; MB=3.00019944; MTD=3.00000008; XFM=3.00000015; UTC=2018-03-09 20:14:40 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18030920-0049-0000-0000-000044633678 Message-Id: <20180309201421.6150-3-stefanb@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-09_10:,, 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=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803090239 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 fd150dfde277..52c9d338819c 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -111,6 +111,9 @@ struct ima_namespace { struct kref kref; struct user_namespace *user_ns; 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 4b081dbfac07..9e0d5fafdfba 100644 --- a/security/integrity/ima/ima_init_ima_ns.c +++ b/security/integrity/ima/ima_init_ima_ns.c @@ -10,9 +10,15 @@ #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 7ab4322c88ae..03acf1431868 100644 --- a/security/integrity/ima/ima_ns.c +++ b/security/integrity/ima/ima_ns.c @@ -73,10 +73,24 @@ struct ima_namespace *copy_ima(struct user_namespace *user_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_user_ns(ns->user_ns); put_ima_ns(ns->parent); + free_ns_status_cache(ns); kfree(ns); } @@ -89,3 +103,106 @@ 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; +} -- 2.13.6