[RFC PATCH 1/5] ima: extend clone() with IMA namespace support
Mehmet Kayaalp
mkayaalp at linux.vnet.ibm.com
Thu Jul 20 22:50:29 UTC 2017
From: Yuqiong Sun <suny at us.ibm.com>
Add new CONFIG_IMA_NS config option. Let clone() create a new IMA
namespace upon CLONE_NEWNS flag. Add ima_ns data structure in nsproxy.
ima_ns is allocated and freed upon IMA namespace creation and exit.
Currently, the ima_ns contains no useful IMA data but only a dummy
interface. This patch creates the framework for namespacing the different
aspects of IMA (eg. IMA-audit, IMA-measurement, IMA-appraisal).
Signed-off-by: Yuqiong Sun <suny at us.ibm.com>
Changelog:
* Use CLONE_NEWNS instead of a new CLONE_NEWIMA flag
* Use existing ima.h headers
* Move the ima_namespace.c to security/integrity/ima/ima_ns.c
* Fix typo INFO->INO
* Each namespace free's itself, removed recursively free'ing
until init_ima_ns from free_ima_ns()
Signed-off-by: Mehmet Kayaalp <mkayaalp at linux.vnet.ibm.com>
---
fs/proc/namespaces.c | 3 +
include/linux/ima.h | 37 ++++++++
include/linux/nsproxy.h | 1 +
include/linux/proc_ns.h | 2 +
init/Kconfig | 8 ++
kernel/nsproxy.c | 15 ++++
security/integrity/ima/Makefile | 1 +
security/integrity/ima/ima.h | 9 ++
security/integrity/ima/ima_init.c | 4 +
security/integrity/ima/ima_ns.c | 183 ++++++++++++++++++++++++++++++++++++++
10 files changed, 263 insertions(+)
create mode 100644 security/integrity/ima/ima_ns.c
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 3803b24..222a64e 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -32,6 +32,9 @@ static const struct proc_ns_operations *ns_entries[] = {
#ifdef CONFIG_CGROUPS
&cgroupns_operations,
#endif
+#ifdef CONFIG_IMA_NS
+ &imans_operations,
+#endif
};
static const char *proc_ns_get_link(struct dentry *dentry,
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 0e4647e..11e4841 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -105,4 +105,41 @@ static inline int ima_inode_removexattr(struct dentry *dentry,
return 0;
}
#endif /* CONFIG_IMA_APPRAISE */
+
+struct ima_namespace {
+ struct kref kref;
+ struct user_namespace *user_ns;
+ struct ns_common ns;
+ struct ima_namespace *parent;
+};
+
+extern struct ima_namespace init_ima_ns;
+
+#ifdef CONFIG_IMA_NS
+void put_ima_ns(struct ima_namespace *ns);
+struct ima_namespace *copy_ima(unsigned long flags,
+ struct user_namespace *user_ns,
+ struct ima_namespace *old_ns);
+static inline struct ima_namespace *get_current_ns(void)
+{
+ return current->nsproxy->ima_ns;
+}
+#else
+static inline void put_ima_ns(struct ima_namespace *ns)
+{
+ return;
+}
+
+static inline struct ima_namespace *copy_ima(unsigned long flags,
+ struct user_namespace *user_ns,
+ struct ima_namespace *old_ns)
+{
+ return old_ns;
+}
+
+static inline struct ima_namespace *get_current_ns(void)
+{
+ return NULL;
+}
+#endif /* CONFIG_IMA_NS */
#endif /* _LINUX_IMA_H */
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index ac0d65b..a97031d 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -35,6 +35,7 @@ struct nsproxy {
struct pid_namespace *pid_ns_for_children;
struct net *net_ns;
struct cgroup_namespace *cgroup_ns;
+ struct ima_namespace *ima_ns;
};
extern struct nsproxy init_nsproxy;
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index 58ab28d..c7c1239 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -31,6 +31,7 @@ extern const struct proc_ns_operations pidns_for_children_operations;
extern const struct proc_ns_operations userns_operations;
extern const struct proc_ns_operations mntns_operations;
extern const struct proc_ns_operations cgroupns_operations;
+extern const struct proc_ns_operations imans_operations;
/*
* We always define these enumerators
@@ -42,6 +43,7 @@ enum {
PROC_USER_INIT_INO = 0xEFFFFFFDU,
PROC_PID_INIT_INO = 0xEFFFFFFCU,
PROC_CGROUP_INIT_INO = 0xEFFFFFFBU,
+ PROC_IMA_INIT_INO = 0xEFFFFFFAU,
};
#ifdef CONFIG_PROC_FS
diff --git a/init/Kconfig b/init/Kconfig
index 1d3475f..339f84d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1287,6 +1287,14 @@ config NET_NS
help
Allow user space to create what appear to be multiple instances
of the network stack.
+config IMA_NS
+ bool "IMA namespace"
+ depends on IMA
+ default y
+ help
+ Allow the creation of IMA namespaces for each mount namespace.
+ Namespaced IMA data enables having IMA features work separately
+ for each mount namespace.
endif # NAMESPACES
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index f6c5d33..85be341 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -27,6 +27,7 @@
#include <linux/syscalls.h>
#include <linux/cgroup.h>
#include <linux/perf_event.h>
+#include <linux/ima.h>
static struct kmem_cache *nsproxy_cachep;
@@ -44,6 +45,9 @@ struct nsproxy init_nsproxy = {
#ifdef CONFIG_CGROUPS
.cgroup_ns = &init_cgroup_ns,
#endif
+#ifdef CONFIG_IMA_NS
+ .ima_ns = &init_ima_ns,
+#endif
};
static inline struct nsproxy *create_nsproxy(void)
@@ -110,8 +114,17 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
goto out_net;
}
+ new_nsp->ima_ns = copy_ima(flags, user_ns, tsk->nsproxy->ima_ns);
+ if (IS_ERR(new_nsp->ima_ns)) {
+ err = PTR_ERR(new_nsp->ima_ns);
+ goto out_ima;
+ }
+
return new_nsp;
+out_ima:
+ if (new_nsp->ima_ns)
+ put_ima_ns(new_nsp->ima_ns);
out_net:
put_cgroup_ns(new_nsp->cgroup_ns);
out_cgroup:
@@ -181,6 +194,8 @@ void free_nsproxy(struct nsproxy *ns)
if (ns->pid_ns_for_children)
put_pid_ns(ns->pid_ns_for_children);
put_cgroup_ns(ns->cgroup_ns);
+ if (ns->ima_ns)
+ put_ima_ns(ns->ima_ns);
put_net(ns->net_ns);
kmem_cache_free(nsproxy_cachep, ns);
}
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 29f198b..20493f0 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
ima_policy.o ima_template.o ima_template_lib.o
ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
+ima-$(CONFIG_IMA_NS) += ima_ns.o
ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d52b487..8a8234a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -291,6 +291,15 @@ static inline int ima_read_xattr(struct dentry *dentry,
#endif /* CONFIG_IMA_APPRAISE */
+#ifdef CONFIG_IMA_NS
+int ima_ns_init(void);
+#else
+static inline int ima_ns_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_IMA_NS */
+
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 2967d49..7f884a7 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -137,5 +137,9 @@ int __init ima_init(void)
ima_init_policy();
+ rc = ima_ns_init();
+ if (rc != 0)
+ return rc;
+
return ima_fs_init();
}
diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c
new file mode 100644
index 0000000..383217b
--- /dev/null
+++ b/security/integrity/ima/ima_ns.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Yuqiong Sun <suny at us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#include <linux/export.h>
+#include <linux/user_namespace.h>
+#include <linux/proc_ns.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/ima.h>
+
+#include "ima.h"
+
+static void get_ima_ns(struct ima_namespace *ns);
+
+int ima_init_namespace(struct ima_namespace *ns)
+{
+ return 0;
+}
+
+int ima_ns_init(void)
+{
+ return ima_init_namespace(&init_ima_ns);
+}
+
+static struct ima_namespace *create_ima_ns(void)
+{
+ struct ima_namespace *ima_ns;
+
+ ima_ns = kmalloc(sizeof(*ima_ns), GFP_KERNEL);
+ if (ima_ns)
+ kref_init(&ima_ns->kref);
+
+ return ima_ns;
+}
+
+/**
+ * Clone a new ns copying an original ima namespace, setting refcount to 1
+ *
+ * @old_ns: old ima namespace to clone
+ * @user_ns: user namespace that current task runs in
+ * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise
+ */
+static struct ima_namespace *clone_ima_ns(struct user_namespace *user_ns,
+ struct ima_namespace *old_ns)
+{
+ struct ima_namespace *ns;
+ int err;
+
+ ns = create_ima_ns();
+ if (!ns)
+ return ERR_PTR(-ENOMEM);
+
+ err = ns_alloc_inum(&ns->ns);
+ if (err) {
+ kfree(ns);
+ return ERR_PTR(err);
+ }
+
+ ns->ns.ops = &imans_operations;
+ get_ima_ns(old_ns);
+ ns->parent = old_ns;
+ ns->user_ns = get_user_ns(user_ns);
+
+ ima_init_namespace(ns);
+
+ return ns;
+}
+
+/**
+ * Copy task's ima namespace, or clone it if flags specifies CLONE_NEWNS.
+ *
+ * @flags: flags used in the clone syscall
+ * @user_ns: user namespace that current task runs in
+ * @old_ns: old ima namespace to clone
+ */
+
+struct ima_namespace *copy_ima(unsigned long flags,
+ struct user_namespace *user_ns,
+ struct ima_namespace *old_ns)
+{
+ struct ima_namespace *new_ns;
+
+ BUG_ON(!old_ns);
+ get_ima_ns(old_ns);
+
+ if (!(flags & CLONE_NEWNS))
+ return old_ns;
+
+ new_ns = clone_ima_ns(user_ns, old_ns);
+ put_ima_ns(old_ns);
+
+ return new_ns;
+}
+
+static void destroy_ima_ns(struct ima_namespace *ns)
+{
+ put_user_ns(ns->user_ns);
+ ns_free_inum(&ns->ns);
+ kfree(ns);
+}
+
+static void free_ima_ns(struct kref *kref)
+{
+ struct ima_namespace *ns;
+
+ ns = container_of(kref, struct ima_namespace, kref);
+ destroy_ima_ns(ns);
+}
+
+static void get_ima_ns(struct ima_namespace *ns)
+{
+ kref_get(&ns->kref);
+}
+
+void put_ima_ns(struct ima_namespace *ns)
+{
+ kref_put(&ns->kref, free_ima_ns);
+}
+
+static inline struct ima_namespace *to_ima_ns(struct ns_common *ns)
+{
+ return container_of(ns, struct ima_namespace, ns);
+}
+
+static struct ns_common *imans_get(struct task_struct *task)
+{
+ struct ima_namespace *ns = NULL;
+ struct nsproxy *nsproxy;
+
+ task_lock(task);
+ nsproxy = task->nsproxy;
+ if (nsproxy) {
+ ns = nsproxy->ima_ns;
+ get_ima_ns(ns);
+ }
+ task_unlock(task);
+
+ return ns ? &ns->ns : NULL;
+}
+
+static void imans_put(struct ns_common *ns)
+{
+ put_ima_ns(to_ima_ns(ns));
+}
+
+static int imans_install(struct nsproxy *nsproxy, struct ns_common *new)
+{
+ struct ima_namespace *ns = to_ima_ns(new);
+
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
+ !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+ return -EPERM;
+
+ get_ima_ns(ns);
+ put_ima_ns(nsproxy->ima_ns);
+ nsproxy->ima_ns = ns;
+ return 0;
+}
+
+const struct proc_ns_operations imans_operations = {
+ .name = "ima",
+ .type = CLONE_NEWNS,
+ .get = imans_get,
+ .put = imans_put,
+ .install = imans_install,
+};
+
+struct ima_namespace init_ima_ns = {
+ .kref = KREF_INIT(2),
+ .user_ns = &init_user_ns,
+ .ns.inum = PROC_IMA_INIT_INO,
+#ifdef CONFIG_IMA_NS
+ .ns.ops = &imans_operations,
+#endif
+ .parent = NULL,
+};
+EXPORT_SYMBOL(init_ima_ns);
--
2.9.4
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
More information about the Linux-security-module-archive
mailing list