From: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: linux-integrity-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: mkayaalp-4hyTIkVWTs8LubxHQvXPfYdd74u8MsAO@public.gmane.org,
Mehmet Kayaalp
<mkayaalp-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
sunyuqiong1988-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
david.safford-JJi787mZWgc@public.gmane.org,
James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org,
linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org,
zohar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org
Subject: [RFC PATCH v3 2/3] ima: Add ns_status for storing namespaced iint data
Date: Tue, 27 Mar 2018 09:57:17 -0400 [thread overview]
Message-ID: <1522159038-14175-3-git-send-email-stefanb__25424.1468072452$1522158949$gmane$org@linux.vnet.ibm.com> (raw)
In-Reply-To: <1522159038-14175-1-git-send-email-stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
From: Mehmet Kayaalp <mkayaalp-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
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 <mkayaalp-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
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 <linux/export.h>
#include <linux/user_namespace.h>
#include <linux/ima.h>
+#include <linux/slab.h>
+
+#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;
+}
--
2.14.3
next prev parent reply other threads:[~2018-03-27 13:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1522159038-14175-1-git-send-email-stefanb@linux.vnet.ibm.com>
[not found] ` <1522159038-14175-1-git-send-email-stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-03-27 13:57 ` [RFC PATCH v3 1/3] ima: extend clone() with IMA namespace support Stefan Berger
[not found] ` <1522159038-14175-2-git-send-email-stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-03-27 23:01 ` Eric W. Biederman
[not found] ` <87sh8lcecn.fsf@xmission.com>
[not found] ` <87sh8lcecn.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2018-03-28 11:10 ` Stefan Berger
2018-04-13 16:25 ` Mimi Zohar
[not found] ` <bc03161e-394b-bf4d-48c4-858dcf05458a@linux.vnet.ibm.com>
[not found] ` <bc03161e-394b-bf4d-48c4-858dcf05458a-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-03-28 12:14 ` Dr. Greg Wettstein
2018-04-18 15:59 ` John Johansen
[not found] ` <20180328121418.GA24712@wind.enjellic.com>
[not found] ` <20180328121418.GA24712-DHO+NtfOqB5PEDpkEIzg7wC/G2K4zDHf@public.gmane.org>
2018-03-28 12:44 ` Stefan Berger
[not found] ` <1523636702.3272.63.camel@linux.vnet.ibm.com>
[not found] ` <1523636702.3272.63.camel-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-04-18 16:09 ` John Johansen
[not found] ` <d8c30d7d-c679-9323-7a25-d3148e9b96c6@canonical.com>
[not found] ` <d8c30d7d-c679-9323-7a25-d3148e9b96c6-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2018-04-18 19:57 ` Mimi Zohar
[not found] ` <1524081472.3272.319.camel@linux.vnet.ibm.com>
[not found] ` <1524081472.3272.319.camel-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-04-18 20:12 ` Eric W. Biederman
[not found] ` <87wox4s282.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2018-04-18 20:27 ` Mimi Zohar
2018-04-18 21:32 ` John Johansen
[not found] ` <8895cb9c-7b9e-2f82-e3d8-a15f5fc26e25@canonical.com>
[not found] ` <8895cb9c-7b9e-2f82-e3d8-a15f5fc26e25-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2018-04-19 11:03 ` Stefan Berger
[not found] ` <2103bbb9-3f2a-78f8-f7ad-28859659973f@linux.vnet.ibm.com>
[not found] ` <2103bbb9-3f2a-78f8-f7ad-28859659973f-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-04-19 15:35 ` John Johansen
[not found] ` <f84ae8af-fa5b-9f31-fbef-5a49f90dd45a@canonical.com>
[not found] ` <f84ae8af-fa5b-9f31-fbef-5a49f90dd45a-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2018-04-26 21:18 ` Stefan Berger
[not found] ` <0d2b2635-d7fb-d240-7dd0-2a81014c58ba@linux.vnet.ibm.com>
[not found] ` <0d2b2635-d7fb-d240-7dd0-2a81014c58ba-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2018-04-27 0:49 ` Eric W. Biederman
2018-03-27 13:57 ` Stefan Berger [this message]
2018-03-27 13:57 ` [RFC PATCH v3 3/3] ima: mamespace audit status flags Stefan Berger
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