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Date: Fri, 19 Feb 2010 01:36:20 -0800
From: john.johansen@...onical.com
To: linux-kernel@...r.kernel.org
Cc: linux-security-module@...r.kernel.org,
John Johansen <john.johansen@...onical.com>
Subject: [PATCH 04/12] The basic routines and defines for AppArmor policy. AppArmor policy is defined by a few basic components. profiles - the basic unit of confinement contain all the information to enforce policy on a task
From: John Johansen <john.johansen@...onical.com>
Profiles tend to be named after an executable that they
will attach to but this is not required.
namespaces - a container for a set of profiles that will be used
during attachment and transitions between profiles.
sids - which provide a unique id for each profile
Signed-off-by: John Johansen <john.johansen@...onical.com>
---
security/apparmor/include/policy.h | 291 ++++++++++
security/apparmor/include/sid.h | 45 ++
security/apparmor/policy.c | 1079 ++++++++++++++++++++++++++++++++++++
security/apparmor/sid.c | 70 +++
4 files changed, 1485 insertions(+), 0 deletions(-)
create mode 100644 security/apparmor/include/policy.h
create mode 100644 security/apparmor/include/sid.h
create mode 100644 security/apparmor/policy.c
create mode 100644 security/apparmor/sid.c
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
new file mode 100644
index 0000000..d49f768
--- /dev/null
+++ b/security/apparmor/include/policy.h
@@ -0,0 +1,291 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor policy definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * 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.
+ */
+
+#ifndef __AA_POLICY_H
+#define __AA_POLICY_H
+
+#include <linux/capability.h>
+#include <linux/cred.h>
+#include <linux/kref.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+
+#include "apparmor.h"
+#include "audit.h"
+#include "capability.h"
+#include "domain.h"
+#include "file.h"
+#include "net.h"
+#include "resource.h"
+
+extern const char *profile_mode_names[];
+#define APPARMOR_NAMES_MAX_INDEX 3
+
+#define COMPLAIN_MODE(_profile) \
+ ((aa_g_profile_mode == APPARMOR_COMPLAIN) || ((_profile) && \
+ (_profile)->mode == APPARMOR_COMPLAIN))
+
+#define DO_KILL(_profile) \
+ ((aa_g_profile_mode == APPARMOR_KILL) || ((_profile) && \
+ (_profile)->mode == APPARMOR_KILL))
+
+#define PROFILE_IS_HAT(_profile) \
+ ((_profile) && (_profile)->flags & PFLAG_HAT)
+
+/*
+ * FIXME: currently need a clean way to replace and remove profiles as a
+ * set. It should be done at the namespace level.
+ * Either, with a set of profiles loaded at the namespace level or via
+ * a mark and remove marked interface.
+ */
+enum profile_mode {
+ APPARMOR_ENFORCE, /* enforce access rules */
+ APPARMOR_COMPLAIN, /* allow and log access violations */
+ APPARMOR_KILL, /* kill task on access violation */
+};
+
+enum profile_flags {
+ PFLAG_HAT = 1, /* profile is a hat */
+ PFLAG_UNCONFINED = 2, /* profile is the unconfined profile */
+ PFLAG_NULL = 4, /* profile is null learning profile */
+ PFLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */
+ PFLAG_IMMUTABLE = 0x10, /* don't allow changes/replacement */
+ PFLAG_USER_DEFINED = 0x20, /* user based profile */
+ PFLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
+ PFLAG_MMAP_MIN_ADDR = 0x80, /* profile controls mmap_min_addr */
+ PFLAG_OLD_NULL_TRANS = 0x100, /* use // as the null transition */
+
+ /* These flags must coorespond with PATH_flags */
+ PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
+};
+
+#define AA_NEW_SID 0
+
+struct aa_profile;
+
+/* struct aa_policy - common part of both namespaces and profiles
+ * @name: name of the object
+ * @hname - The hierarchical name
+ * @count: reference count of the obj
+ * @list: list policy object is on
+ * @profiles: head of the profiles list contained in the object
+ */
+struct aa_policy {
+ char *name;
+ char *hname;
+ struct kref count;
+ struct list_head list;
+ struct list_head profiles;
+};
+
+/* struct aa_ns_acct - accounting of profiles in namespace
+ * @max_size: maximum space allowed for all profiles in namespace
+ * @max_count: maximum number of profiles that can be in this namespace
+ * @size: current size of profiles
+ * @count: current count of profiles (includes null profiles)
+ */
+struct aa_ns_acct {
+ int max_size;
+ int max_count;
+ int size;
+ int count;
+};
+
+/* struct aa_namespace - namespace for a set of profiles
+ * @base: common policy
+ * @parent: parent of namespace
+ * @lock: lock for modifying the object
+ * @acct: accounting for the namespace
+ * @unconfined: special unconfined profile for the namespace
+ * @sub_ns: list of namespaces under the current namespace.
+ *
+ * An aa_namespace defines the set profiles that are searched to determine
+ * which profile to attach to a task. Profiles can not be shared between
+ * aa_namespaces and profile names within a namespace are guarenteed to be
+ * unique. When profiles in seperate namespaces have the same name they
+ * are NOT considered to be equivalent.
+ *
+ * Namespaces are hierarchical and only namespaces and profiles below the
+ * current namespace are visible.
+ *
+ * Namespace names must be unique and can not contain the characters :/\0
+ *
+ * FIXME TODO: add vserver support so a vserer (can it all be done in userspace)
+ */
+struct aa_namespace {
+ struct aa_policy base;
+ struct aa_namespace *parent;
+ rwlock_t lock;
+ struct aa_ns_acct acct;
+ struct aa_profile *unconfined;
+ struct list_head sub_ns;
+};
+
+/* struct aa_profile - basic confinement data
+ * @base - base componets of the profile (name, refcount, lists, lock ...)
+ * @parent: parent of profile
+ * @ns: namespace the profile is in
+ * @replacedby: is set profile that replaced this profile
+ * @xmatch: optional extended matching for unconfined executables names
+ * @xmatch_len: xmatch prefix len, used to determine xmatch priority
+ * @sid: the unique security id number of this profile
+ * @audit: the auditing mode of the profile
+ * @mode: the enforcement mode of the profile
+ * @flags: flags controlling profile behavior
+ * @path_flags: flags controlling path generation behavior
+ * @size: the memory consumed by this profiles rules
+ * @file: The set of rules governing basic file access and domain transitions
+ * @caps: capabilities for the profile
+ * @net: network controls for the profile
+ * @rlimits: rlimits for the profile
+ *
+ * The AppArmor profile contains the basic confinement data. Each profile
+ * has a name, and exist in a namespace. The @name and @exec_match are
+ * used to determine profile attachment against unconfined tasks. All other
+ * attachments are determined by in profile X transition rules.
+ *
+ * The @replacedby field is write protected by the profile lock. Reads
+ * are assumed to be atomic, and are done without locking.
+ *
+ * Profiles have a hierachy where hats and children profiles keep
+ * a reference to their parent.
+ *
+ * Profile names can not begin with a : and can not contain the \0
+ * character. If a profile name begins with / it will be considered when
+ * determining profile attachment on "unconfined" tasks.
+ */
+struct aa_profile {
+ struct aa_policy base;
+ struct aa_profile *parent;
+
+ struct aa_namespace *ns;
+ union {
+ struct aa_profile *replacedby;
+ const char *rename;
+ };
+ struct aa_dfa *xmatch;
+ int xmatch_len;
+ u32 sid;
+ enum audit_mode audit;
+ enum profile_mode mode;
+ u32 flags;
+ u32 path_flags;
+ int size;
+
+ unsigned long mmap_min_addr;
+
+ struct aa_file_rules file;
+ struct aa_caps caps;
+ struct aa_net net;
+ struct aa_rlimit rlimits;
+};
+
+extern struct aa_namespace *root_ns;
+extern enum profile_mode aa_g_profile_mode;
+
+void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
+
+int aa_alloc_root_ns(void);
+void aa_free_root_ns(void);
+void aa_free_namespace_kref(struct kref *kref);
+
+struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
+ const char *name);
+
+static inline struct aa_policy *aa_get_common(struct aa_policy *c)
+{
+ if (c)
+ kref_get(&c->count);
+
+ return c;
+}
+
+static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
+{
+ if (ns)
+ kref_get(&(ns->base.count));
+
+ return ns;
+}
+
+static inline void aa_put_namespace(struct aa_namespace *ns)
+{
+ if (ns)
+ kref_put(&ns->base.count, aa_free_namespace_kref);
+}
+
+struct aa_profile *aa_alloc_profile(const char *name);
+struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat);
+void aa_free_profile_kref(struct kref *kref);
+struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
+struct aa_profile *aa_find_profile(struct aa_namespace *ns, const char *name);
+struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name);
+
+ssize_t aa_interface_replace_profiles(void *udata, size_t size, bool add_only);
+ssize_t aa_interface_remove_profiles(char *name, size_t size);
+
+#define unconfined(X) ((X)->flags & PFLAG_UNCONFINED)
+
+/**
+ * aa_newest_version - find the newest version of @profile
+ * @profile: the profile to check for newer versions of
+ *
+ * Find the newest version of @profile, if @profile is the newest version
+ * return @profile.
+ *
+ * NOTE: the profile returned is not refcounted, The refcount on @profile
+ * must be held until the caller decides what to do with the returned newest
+ * version.
+ */
+static inline struct aa_profile *aa_newest_version(struct aa_profile *profile)
+{
+ if (unlikely(profile && profile->replacedby))
+ for (; profile->replacedby; profile = profile->replacedby) ;
+
+ return profile;
+}
+
+/**
+ * aa_get_profile - increment refcount on profile @p
+ * @p: profile
+ */
+static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
+{
+ if (p)
+ kref_get(&(p->base.count));
+
+ return p;
+}
+
+/**
+ * aa_put_profile - decrement refcount on profile @p
+ * @p: profile
+ */
+static inline void aa_put_profile(struct aa_profile *p)
+{
+ if (p)
+ kref_put(&p->base.count, aa_free_profile_kref);
+}
+
+static inline int AUDIT_MODE(struct aa_profile *profile)
+{
+ if (aa_g_audit != AUDIT_NORMAL)
+ return aa_g_audit;
+ if (profile)
+ return profile->audit;
+ return AUDIT_NORMAL;
+}
+
+#endif /* __AA_POLICY_H */
diff --git a/security/apparmor/include/sid.h b/security/apparmor/include/sid.h
new file mode 100644
index 0000000..2a3059b
--- /dev/null
+++ b/security/apparmor/include/sid.h
@@ -0,0 +1,45 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor security identifier (sid) definitions
+ *
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * 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.
+ */
+
+#ifndef __AA_SID_H
+#define __AA_SID_H
+
+#include <linux/types.h>
+
+struct aa_profile;
+
+#define AA_ALLOC_USR_SID 1
+#define AA_ALLOC_SYS_SID 0
+
+u32 aa_alloc_sid(int is_usr);
+void aa_free_sid(u32 sid);
+int aa_add_sid_profile(u32 sid, struct aa_profile *profile);
+int aa_replace_sid_profile(u32 sid, struct aa_profile *profile);
+struct aa_profile *aa_get_sid_profile(u32 sid);
+
+static inline u32 aa_compound_sid(u32 sys, u32 usr)
+{
+ return sys | usr;
+}
+
+static inline u32 aa_usr_sid(u32 sid)
+{
+ return sid & 0xffff0000;
+}
+
+static inline u32 aa_sys_sid(u32 sid)
+{
+ return sid & 0xffff;
+}
+
+#endif /* __AA_SID_H */
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
new file mode 100644
index 0000000..4a740ff
--- /dev/null
+++ b/security/apparmor/policy.c
@@ -0,0 +1,1079 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor policy manipulation functions
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * 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.
+ *
+ *
+ * AppArmor policy is based around profiles, which contain the rules a
+ * task is confined by. Every task in the sytem has a profile attached
+ * to it determined either by matching "unconfined" tasks against the
+ * visible set of profiles or by following a profiles attachment rules.
+ *
+ * Each profile exists in a profile namespace which is a container of
+ * visible profiles. Each namespace contains a special "unconfined" profile,
+ * which doesn't enforce any confinement on a task beyond DAC.
+ *
+ * Namespace and profile names can be written together in either
+ * of two syntaxes.
+ * :namespace:profile - used by kernel interfaces for easy detection
+ * namespace://profile - used by policy
+ *
+ * Profile names can not start with : or @ or ^ and may not contain \0
+ *
+ * Reserved profile names
+ * unconfined - special automatically generated unconfined profile
+ * inherit - special name to indicate profile inheritance
+ * null-XXXX-YYYY - special automically generated learning profiles
+ *
+ * Namespace names may not start with / or @ and may not contain \0 or :
+ * Reserved namespace namespace
+ * user-XXXX - user defined profiles
+ *
+ * a // in a profile or namespace name indicates a hierarcical name with the
+ * name before the // being the parent and the name after the child.
+ *
+ * Profile and namespace hierachies serve two different but similar purposes.
+ * The namespace contains the set of visible profiles that are considered
+ * for attachment. The hierarchy of namespaces allows for virtualizing
+ * the namespace so that for example a chroot can have its own set of profiles
+ * which may define some local user namespaces.
+ * The profile hierachy severs two distinct purposes,
+ * - it allows for sub profiles or hats, which allows an application to run
+ * subprograms under its own profile with different restriction than it
+ * self, and not have it use the system profile.
+ * eg. if a mail program starts an editor, the policy might make the
+ * restrictions tighter on the editor tighter than the mail program,
+ * and definitely different than general editor restrictions
+ * - it allows for binary hierarchy of profiles, so that execution history
+ * is preserved. This feature isn't exploited by AppArmor reference policy
+ * but is allowed. NOTE: this is currently suboptimal because profile
+ * aliasing is not currently implemented so that a profile for each
+ * level must be defined.
+ * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
+ * from /bin/bash
+ *
+ * A profile or namespace name that can contain one or more // seperators
+ * is refered to as an hname (hierarchical).
+ * eg. /bin/bash//bin/ls
+ *
+ * An fqname is a name that may contain both namespace and profile hnames.
+ * eg. :ns:/bin/bash//bin/ls
+ *
+ * NOTES:
+ * - locking of profile lists is currently fairly coarse. All profile
+ * lists within a namespace use the namespace lock.
+ * FIXME: move profile lists to using rcu_lists
+ */
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#include "include/apparmor.h"
+#include "include/capability.h"
+#include "include/context.h"
+#include "include/file.h"
+#include "include/ipc.h"
+#include "include/match.h"
+#include "include/path.h"
+#include "include/policy.h"
+#include "include/policy_unpack.h"
+#include "include/resource.h"
+#include "include/sid.h"
+
+
+/* root profile namespace */
+struct aa_namespace *root_ns;
+
+const char *profile_mode_names[] = {
+ "enforce",
+ "complain",
+ "kill",
+};
+
+/**
+ * hname_tail - find the last component of an hname
+ * @name: hname to find the tail component of
+ *
+ * Returns: the tail name component of an hname
+ */
+static const char *hname_tail(const char *hname)
+{
+ char *split;
+ /* check for namespace which begins with a : and ends with : or \0 */
+ hname = strstrip((char *)hname);
+ for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
+ hname = split + 2;
+
+ return hname;
+}
+
+/**
+ * policy_init - initialize a policy structure
+ * @policy: policy to initialize
+ * @name: name of the policy, init will make a copy of it
+ */
+static bool policy_init(struct aa_policy *policy, const char *name)
+{
+ /* freed by policy_free */
+ policy->hname = kstrdup(name, GFP_KERNEL);
+ if (!policy->hname)
+ return 0;
+ /* base.name is a substring of fqname */
+ policy->name = (char *)hname_tail(policy->hname);
+
+ INIT_LIST_HEAD(&policy->list);
+ INIT_LIST_HEAD(&policy->profiles);
+ kref_init(&policy->count);
+
+ return 1;
+}
+
+/**
+ * policy_destroy - free the elements referenced by @policy
+ * @policy: policy that is to have its elements freed
+ */
+static void policy_destroy(struct aa_policy *policy)
+{
+ /* still contains profiles -- invalid */
+ if (!list_empty(&policy->profiles)) {
+ AA_ERROR("%s: internal error, "
+ "policy '%s' still contains profiles\n",
+ __func__, policy->name);
+ BUG();
+ }
+ if (!list_empty(&policy->list)) {
+ AA_ERROR("%s: internal error, policy '%s' still on list\n",
+ __func__, policy->name);
+ BUG();
+ }
+
+ /* don't free name as its a subset of hname */
+ kzfree(policy->hname);
+}
+
+/**
+ * __policy_find - find a policy by @name on a policy list
+ * @head: list to search
+ * @name: name to search for
+ *
+ * Requires: correct locks for the @head list be held
+ *
+ * Returns: policy that match @name or NULL if not found
+ */
+static struct aa_policy *__policy_find(struct list_head *head, const char *name)
+{
+ struct aa_policy *policy;
+
+ list_for_each_entry(policy, head, list) {
+ if (!strcmp(policy->name, name))
+ return policy;
+ }
+ return NULL;
+}
+
+/**
+ * __policy_strn_find - find a policy thats name matches @len chars of @str
+ * @head: list to search
+ * @str: string to search for
+ * @len: length of match required
+ *
+ * Requires: correct locks for the @head list be held
+ *
+ * Returns: policy that match @str or NULL if not found
+ *
+ * if @len == strlen(@strlen) then this is equiv to __policy_find
+ * other wise it allows searching for policy by a partial match of name
+ */
+static struct aa_policy *__policy_strn_find(struct list_head *head,
+ const char *str, int len)
+{
+ struct aa_policy *policy;
+
+ list_for_each_entry(policy, head, list) {
+ if (aa_strneq(policy->name, str, len))
+ return policy;
+ }
+
+ return NULL;
+}
+
+/*
+ * Routines for AppArmor namespaces
+ */
+
+/**
+ * aa_alloc_namespace - allocate, initialize and return a new namespace
+ * @name: a preallocated name
+ * Returns NULL on failure.
+ */
+static struct aa_namespace *aa_alloc_namespace(const char *name)
+{
+ struct aa_namespace *ns;
+
+ ns = kzalloc(sizeof(*ns), GFP_KERNEL);
+ AA_DEBUG("%s(%p)\n", __func__, ns);
+ if (!ns)
+ return NULL;
+
+ if (!policy_init(&ns->base, name))
+ goto fail_ns;
+ INIT_LIST_HEAD(&ns->sub_ns);
+ rwlock_init(&ns->lock);
+
+ /*
+ * null profile is not added to the profile list,
+ * released by aa_free_namespace
+ */
+ ns->unconfined = aa_alloc_profile("unconfined");
+ if (!ns->unconfined)
+ goto fail_unconfined;
+
+ ns->unconfined->sid = aa_alloc_sid(AA_ALLOC_SYS_SID);
+ ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
+ PFLAG_IMMUTABLE;
+
+ /*
+ * released by aa_free_namespace, however aa_remove_namespace breaks
+ * the cyclic references (ns->unconfined, and unconfined->ns) and
+ * replaces with refs to parent namespace unconfined
+ */
+ ns->unconfined->ns = aa_get_namespace(ns);
+
+ return ns;
+
+fail_unconfined:
+ kzfree(ns->base.name);
+fail_ns:
+ kzfree(ns);
+ return NULL;
+}
+
+/**
+ * aa_free_namespace - free a profile namespace
+ * @namespace: the namespace to free
+ *
+ * Requires: All references to the namespace must have been put, if the
+ * namespace was referenced by a profile confining a task,
+ */
+static void aa_free_namespace(struct aa_namespace *ns)
+{
+ if (!ns)
+ return;
+
+ policy_destroy(&ns->base);
+ aa_put_namespace(ns->parent);
+
+ if (ns->unconfined && ns->unconfined->ns == ns)
+ ns->unconfined->ns = NULL;
+
+ aa_put_profile(ns->unconfined);
+ kzfree(ns);
+}
+
+/**
+ * aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
+ * @kr: kref callback for freeing of a namespace
+ */
+void aa_free_namespace_kref(struct kref *kref)
+{
+ aa_free_namespace(container_of(kref, struct aa_namespace, base.count));
+}
+
+/**
+ * __aa_find_namespace - find a namespace on a list by @name
+ * @name - name of namespace to look for
+ *
+ * Return: unrefcounted namespace
+ *
+ * Requires: ns lock be held
+ */
+static struct aa_namespace *__aa_find_namespace(struct list_head *head,
+ const char *name)
+{
+ return (struct aa_namespace *)__policy_find(head, name);
+}
+
+/**
+ * aa_find_namespace - look up a profile namespace on the namespace list
+ * @root: namespace to search in
+ * @name: name of namespace to find
+ *
+ * Return: a pointer to the namespace on the list, or NULL if no namespace
+ * called @name exists.
+ *
+ * refcount released by caller
+ */
+struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
+ const char *name)
+{
+ struct aa_namespace *ns = NULL;
+
+ read_lock(&root->lock);
+ ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
+ read_unlock(&root->lock);
+
+ return ns;
+}
+
+/**
+ * aa_prepare_namespace - find an existing or create a new namespace of @name
+ * @name: the namespace to find or add
+ *
+ * Return: refcounted namespace or NULL if failed to create one
+ */
+static struct aa_namespace *aa_prepare_namespace(const char *name)
+{
+ struct aa_namespace *ns, *root;
+
+ root = aa_current_profile()->ns;
+
+ write_lock(&root->lock);
+ if (name)
+ /* released by caller */
+ ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
+ else
+ /* released by caller */
+ ns = aa_get_namespace(root);
+ if (!ns) {
+ /* name && namespace not found */
+ struct aa_namespace *new_ns;
+ write_unlock(&root->lock);
+ new_ns = aa_alloc_namespace(name);
+ if (!new_ns)
+ return NULL;
+ write_lock(&root->lock);
+ /* test for race when new_ns was allocated */
+ ns = __aa_find_namespace(&root->sub_ns, name);
+ if (!ns) {
+ /* add parent ref */
+ new_ns->parent = aa_get_namespace(root);
+
+ list_add(&new_ns->base.list, &root->sub_ns);
+ /* add list ref */
+ ns = aa_get_namespace(new_ns);
+ } else {
+ /* raced so free the new one */
+ aa_free_namespace(new_ns);
+ /* get reference on namespace */
+ aa_get_namespace(ns);
+ }
+ }
+ write_unlock(&root->lock);
+
+ /* return ref */
+ return ns;
+}
+
+/**
+ * __aa_add_profile - add a profile to a list
+ * @list: list to add it to
+ * @profile: the profile to add
+ *
+ * refcount @profile, should be put by __aa_remove_profile
+ *
+ * Requires: namespace lock be held, or list not be shared
+ */
+static void __aa_add_profile(struct list_head *list,
+ struct aa_profile *profile)
+{
+ list_add(&profile->base.list, list);
+ /* get list reference */
+ aa_get_profile(profile);
+}
+
+/**
+ * __aa_remove_profile - remove a profile from the list it is one
+ * @profile: the profile to remove
+ *
+ * remove a profile from the list, warning generally removal should
+ * be done with __aa_replace_profile as most profile removals are
+ * replacements to the unconfined profile.
+ *
+ * put @profile list refcount
+ *
+ * Requires: namespace lock be held, or list not have been live
+ */
+static void __aa_remove_profile(struct aa_profile *profile)
+{
+ list_del_init(&profile->base.list);
+ if (!(profile->flags & PFLAG_NO_LIST_REF))
+ /* release list reference */
+ aa_put_profile(profile);
+}
+
+/**
+ * __aa_replace_profile - replace @old with @new on a list
+ * @old: profile to be replaced
+ * @new: profile to replace @old with
+ *
+ * Will duplicaticate and refcount elements that @new inherits from @old
+ * and will inherit @old children. If new is NULL it will replace to the
+ * unconfined profile for old's namespace.
+ *
+ * refcount @new for list, put @old list refcount
+ *
+ * Requires: namespace list lock be held, or list not be shared
+ */
+static void __aa_replace_profile(struct aa_profile *old,
+ struct aa_profile *new)
+{
+ struct aa_policy *policy;
+ struct aa_profile *child, *tmp;
+
+ if (old->parent)
+ policy = &old->parent->base;
+ else
+ policy = &old->ns->base;
+
+ if (new) {
+ /* released when @new is freed */
+ new->parent = aa_get_profile(old->parent);
+ new->ns = aa_get_namespace(old->ns);
+ new->sid = old->sid;
+ __aa_add_profile(&policy->profiles, new);
+ } else {
+ /* refcount not taken, held via @old refcount */
+ new = old->ns->unconfined;
+ }
+
+ /* inherit children */
+ list_for_each_entry_safe(child, tmp, &old->base.profiles, base.list) {
+ aa_put_profile(child->parent);
+ child->parent = aa_get_profile(new);
+ /* list refcount transfered to @new*/
+ list_move(&child->base.list, &new->base.profiles);
+ }
+
+ /* released by aa_free_profile */
+ old->replacedby = aa_get_profile(new);
+ __aa_remove_profile(old);
+}
+
+/**
+ * __aa_profile_list_release - remove all profiles on the list and put refs
+ * @head: list of profiles
+ *
+ * Requires: namespace lock be held
+ */
+static void __aa_profile_list_release(struct list_head *head)
+{
+ struct aa_profile *profile, *tmp;
+ list_for_each_entry_safe(profile, tmp, head, base.list) {
+ /* release any children lists first */
+ __aa_profile_list_release(&profile->base.profiles);
+ __aa_replace_profile(profile, NULL);
+ }
+}
+
+static void __aa_remove_namespace(struct aa_namespace *ns);
+
+/**
+ * __aa_ns_list_release - remove all profile namespaces on the list put refs
+ * @head: list of profile namespaces
+ *
+ * Requires: namespace lock be held
+ */
+static void __aa_ns_list_release(struct list_head *head)
+{
+ struct aa_namespace *ns, *tmp;
+ list_for_each_entry_safe(ns, tmp, head, base.list)
+ __aa_remove_namespace(ns);
+
+}
+
+/**
+ * aa_destroy_namespace - remove everything contained by @ns
+ * @ns: namespace to have it contents removed
+ */
+static void aa_destroy_namespace(struct aa_namespace *ns)
+{
+ if (!ns)
+ return;
+
+ write_lock(&ns->lock);
+ /* release all profiles in this namespace */
+ __aa_profile_list_release(&ns->base.profiles);
+
+ /* release all sub namespaces */
+ __aa_ns_list_release(&ns->sub_ns);
+
+ write_unlock(&ns->lock);
+}
+
+/**
+ * __aa_remove_namespace - remove a namespace and all its children
+ * @ns: namespace to be removed
+ *
+ * Requires: ns->parent->lock be held and ns removed from parent.
+ */
+static void __aa_remove_namespace(struct aa_namespace *ns)
+{
+ struct aa_profile *unconfined = ns->unconfined;
+
+ /* remove ns from namespace list */
+ list_del_init(&ns->base.list);
+
+ /*
+ * break the ns, unconfined profile cyclic reference and forward
+ * all new unconfined profiles requests to the parent namespace
+ * This will result in all confined tasks that have a profile
+ * being removed, inheriting the parent->unconfined profile.
+ */
+ if (ns->parent)
+ ns->unconfined = aa_get_profile(ns->parent->unconfined);
+
+ aa_destroy_namespace(ns);
+
+ /* release original ns->unconfined ref */
+ aa_put_profile(unconfined);
+ /* release ns->base.list ref, from removal above */
+ aa_put_namespace(ns);
+}
+
+/**
+ * aa_alloc_root_ns - allocate the root profile namespace
+ *
+ * Returns 0 on success else error
+ *
+ */
+int __init aa_alloc_root_ns(void)
+{
+ /* released by aa_free_root_ns - used as list ref*/
+ root_ns = aa_alloc_namespace("root");
+ if (!root_ns)
+ return -ENOMEM;
+
+ return 0;
+}
+
+ /**
+ * aa_free_root_ns - free the root profile namespace
+ */
+void aa_free_root_ns(void)
+ {
+ struct aa_namespace *ns = root_ns;
+ root_ns = NULL;
+
+ aa_destroy_namespace(ns);
+ aa_put_namespace(ns);
+}
+
+/**
+ * aa_alloc_profile - allocate, initialize and return a new profile
+ * @hname: name of the profile
+ *
+ * Returns NULL on failure, else refcounted profile
+ */
+struct aa_profile *aa_alloc_profile(const char *hname)
+{
+ struct aa_profile *profile;
+
+ /* freed by aa_free_profile - usually through aa_put_profile */
+ profile = kzalloc(sizeof(*profile), GFP_KERNEL);
+ if (!profile)
+ return NULL;
+
+ if (!policy_init(&profile->base, hname)) {
+ kzfree(profile);
+ return NULL;
+ }
+
+ /* return ref */
+ return profile;
+}
+
+/**
+ * aa_new_null_profile - create a new null-X learning profile
+ * @parent: profile that caused this profile to be created
+ * @hat: true if the null- learning profile is a hat
+ *
+ * Create a null- complain mode profile used in learning mode. The name of
+ * the profile is unique and follows the format of parent//null-sid.
+ *
+ * null profiles are added to the profile list but the list does not
+ * hold a count on them so that they are automatically released when
+ * not in use.
+ */
+struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
+{
+ struct aa_profile *profile = NULL;
+ char *name;
+ u32 sid = aa_alloc_sid(AA_ALLOC_SYS_SID);
+
+ /* freed below */
+ name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
+ if (!name)
+ goto fail;
+ sprintf(name, "%s//null-%x", parent->base.hname, sid);
+
+ profile = aa_alloc_profile(name);
+ kfree(name);
+ if (!profile)
+ goto fail;
+
+ profile->sid = aa_alloc_sid(AA_ALLOC_SYS_SID);
+ profile->mode = APPARMOR_COMPLAIN;
+ profile->flags = PFLAG_NULL | PFLAG_NO_LIST_REF;
+ if (hat)
+ profile->flags |= PFLAG_HAT;
+
+ /* released on aa_free_profile */
+ profile->parent = aa_get_profile(parent);
+ profile->ns = aa_get_namespace(parent->ns);
+
+ write_lock(&profile->ns->lock);
+ __aa_add_profile(&parent->base.profiles, profile);
+ write_unlock(&profile->ns->lock);
+
+ return profile;
+
+fail:
+ aa_free_sid(sid);
+ return NULL;
+}
+
+/**
+ * aa_free_profile - free a profile
+ * @profile: the profile to free
+ *
+ * Free a profile, its hats and null_profile. All references to the profile,
+ * its hats and null_profile must have been put.
+ *
+ * If the profile was referenced from a task context, aa_free_profile() will
+ * be called from an rcu callback routine, so we must not sleep here.
+ */
+static void aa_free_profile(struct aa_profile *profile)
+{
+ AA_DEBUG("%s(%p)\n", __func__, profile);
+
+ if (!profile)
+ return;
+
+ if (!list_empty(&profile->base.list)) {
+ AA_ERROR("%s: internal error, "
+ "profile '%s' still on ns list\n",
+ __func__, profile->base.name);
+ BUG();
+ }
+
+ /* free children profiles */
+ policy_destroy(&profile->base);
+ aa_put_profile(profile->parent);
+
+ aa_put_namespace(profile->ns);
+
+ aa_free_file_rules(&profile->file);
+ aa_free_cap_rules(&profile->caps);
+ aa_free_net_rules(&profile->net);
+ aa_free_rlimit_rules(&profile->rlimits);
+
+ aa_free_sid(profile->sid);
+ aa_put_dfa(profile->xmatch);
+
+ if (profile->replacedby)
+ aa_put_profile(profile->replacedby);
+
+ kzfree(profile);
+}
+
+/**
+ * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
+ * @kr: kref callback for freeing of a profile
+ */
+void aa_free_profile_kref(struct kref *kref)
+{
+ struct aa_profile *p = container_of(kref, struct aa_profile,
+ base.count);
+
+ aa_free_profile(p);
+}
+
+/* TODO: profile count accounting - setup in remove */
+
+/**
+ * __aa_find_child - find a profile on @head list with a name matching @name
+ * @head: list to search
+ * @name: name of profile
+ *
+ * Requires: ns lock protecting list be held
+ *
+ * Returns unrefcounted profile ptr, or NULL if not found
+ */
+static struct aa_profile *__aa_find_child(struct list_head *head,
+ const char *name)
+{
+ return (struct aa_profile *)__policy_find(head, name);
+}
+
+/**
+ * __aa_strn_find_child - find a profile on @head list using substring of @name
+ * @head: list to search
+ * @name: name of profile
+ * @len: length of @name substring to match
+ *
+ * Requires: ns lock protecting list be held
+ *
+ * Returns unrefcounted profile ptr, or NULL if not found
+ */
+static struct aa_profile *__aa_strn_find_child(struct list_head *head,
+ const char *name, int len)
+{
+ return (struct aa_profile *)__policy_strn_find(head, name, len);
+}
+
+/**
+ * aa_find_child - find a profile by @name in @parent
+ * @parent: profile to search
+ * @name: profile name to search for
+ *
+ * Returns a ref counted profile or NULL if not found
+ */
+struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
+{
+ struct aa_profile *profile;
+
+ read_lock(&parent->ns->lock);
+ profile = aa_get_profile(__aa_find_child(&parent->base.profiles, name));
+ read_unlock(&parent->ns->lock);
+
+ return profile;
+}
+
+/**
+ * __aa_find_parent - lookup the parent of a profile of name @hname
+ * @ns: namespace to lookup profile in
+ * @hname: hierarchical profile name to find parent of
+ *
+ * Lookups up the parent of a fully qualified profile name, the profile
+ * that matches hname does not need to exist, in general this
+ * is used to load a new profile.
+ *
+ * Requires: ns->lock be held
+ *
+ * Returns: unrefcounted policy or NULL if not found
+ */
+static struct aa_policy *__aa_find_parent(struct aa_namespace *ns,
+ const char *hname)
+{
+ struct aa_policy *policy;
+ struct aa_profile *profile = NULL;
+ char *split;
+
+ policy = &ns->base;
+
+ for (split = strstr(hname, "//"); split;) {
+ profile = __aa_strn_find_child(&policy->profiles, hname,
+ split - hname);
+ if (!profile)
+ return NULL;
+ policy = &profile->base;
+ hname = split + 2;
+ split = strstr(hname, "//");
+ }
+ if (!profile)
+ return &ns->base;
+ return &profile->base;
+}
+
+/**
+ * __aa_find_profile - lookup the profile matching @hname
+ * @base: base list to start looking up profile name from
+ * @hname: hierarchical profile name
+ *
+ * Requires: ns->lock be held
+ *
+ * Returns: unrefcounted profile pointer or NULL if not found
+ *
+ * Do a relative name lookup, recursing through profile tree.
+ */
+static struct aa_profile *__aa_find_profile(struct aa_policy *base,
+ const char *hname)
+{
+ struct aa_profile *profile = NULL;
+ char *split;
+
+ for (split = strstr(hname, "//"); split;) {
+ profile = __aa_strn_find_child(&base->profiles, hname,
+ split - hname);
+ if (!profile)
+ return NULL;
+
+ base = &profile->base;
+ hname = split + 2;
+ split = strstr(hname, "//");
+ }
+
+ profile = __aa_find_child(&base->profiles, hname);
+
+ return profile;
+}
+
+/**
+ * aa_find_profile_by_name - find a profile by its full or partial name
+ * @ns: the namespace to start from
+ * @hname: name to do lookup on. Does not contain namespace prefix
+ *
+ * Returns: refcounted profile or NULL if not found
+ */
+struct aa_profile *aa_find_profile(struct aa_namespace *ns, const char *hname)
+{
+ struct aa_profile *profile;
+
+ read_lock(&ns->lock);
+ profile = aa_get_profile(__aa_find_profile(&ns->base, hname));
+ read_unlock(&ns->lock);
+ return profile;
+}
+
+/**
+ * replacement_allowed - test to see if replacement is allowed
+ */
+static bool replacement_allowed(struct aa_profile *profile,
+ struct aa_audit_iface *sa,
+ int add_only)
+{
+ if (profile) {
+ if (profile->flags & PFLAG_IMMUTABLE) {
+ sa->base.info = "cannot replace immutible profile";
+ sa->base.error = -EPERM;
+ return 0;
+ } else if (add_only) {
+ sa->base.info = "profile already exists";
+ sa->base.error = -EEXIST;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+/**
+ * __add_new_profile - simple wrapper around __aa_add_profile
+ * @ns: namespace that profile is being added to
+ * @policy: the policy container to add the profile to
+ * @profile: profile to add
+ *
+ * add a profile to a list and do other required basic allocations
+ */
+static void __add_new_profile(struct aa_namespace *ns,
+ struct aa_policy *policy,
+ struct aa_profile *profile)
+{
+ if (policy != &ns->base)
+ /* released on profile replacement or aa_free_profile */
+ profile->parent = aa_get_profile((struct aa_profile *) policy);
+ __aa_add_profile(&policy->profiles, profile);
+ /* released on aa_free_profile */
+ profile->sid = aa_alloc_sid(AA_ALLOC_SYS_SID);
+ profile->ns = aa_get_namespace(ns);
+}
+
+/**
+ * aa_interface_replace_profiles - replace profile(s) on the profile list
+ * @udata: serialized data stream
+ * @size: size of the serialized data stream
+ * @add_only: true if only doing addition, no replacement allowed
+ *
+ * unpack and replace a profile on the profile list and uses of that profile
+ * by any aa_task_cxt. If the profile does not exist on the profile list
+ * it is added. Return %0 or error.
+ */
+ssize_t aa_interface_replace_profiles(void *udata, size_t size, bool add_only)
+{
+ struct aa_policy *policy;
+ struct aa_profile *old_profile = NULL, *new_profile = NULL;
+ struct aa_profile *rename_profile = NULL;
+ struct aa_namespace *ns;
+ ssize_t error;
+ struct aa_audit_iface sa = {
+ .base.operation = "profile_replace",
+ .base.gfp_mask = GFP_ATOMIC,
+ };
+
+ /* check if loading policy is locked out */
+ if (aa_g_lock_policy) {
+ sa.base.info = "policy locked";
+ sa.base.error = -EACCES;
+ goto fail;
+ }
+
+ /* released below */
+ new_profile = aa_unpack(udata, size, &sa);
+ if (IS_ERR(new_profile)) {
+ sa.base.error = PTR_ERR(new_profile);
+ goto fail;
+ }
+
+ /* released below */
+ ns = aa_prepare_namespace(sa.name2);
+ if (!ns) {
+ sa.base.info = "failed to prepare namespace";
+ sa.base.error = -ENOMEM;
+ goto fail;
+ }
+
+ sa.name = new_profile->base.hname;
+
+ write_lock(&ns->lock);
+ /* no ref on policy only use inside lock */
+ policy = __aa_find_parent(ns, new_profile->base.hname);
+
+ if (!policy) {
+ sa.base.info = "parent does not exist";
+ sa.base.error = -ENOENT;
+ goto audit;
+ }
+
+ old_profile = __aa_find_child(&policy->profiles,
+ new_profile->base.name);
+ /* released below */
+ aa_get_profile(old_profile);
+
+ if (new_profile->rename) {
+ rename_profile = __aa_find_profile(&ns->base,
+ new_profile->rename);
+ /* released below */
+ aa_get_profile(rename_profile);
+
+ /* must be cleared as it is shared with replaced-by */
+ kzfree(new_profile->rename);
+ new_profile->rename = NULL;
+
+ if (!rename_profile) {
+ sa.base.info = "profile to rename does not exist";
+ sa.base.error = -ENOENT;
+ goto audit;
+ }
+ }
+
+ if (!replacement_allowed(old_profile, &sa, add_only))
+ goto audit;
+
+ if (!replacement_allowed(rename_profile, &sa, add_only))
+ goto audit;
+
+audit:
+ if (!old_profile && !rename_profile)
+ sa.base.operation = "profile_load";
+
+ error = aa_audit_iface(&sa);
+
+ if (!error) {
+ if (old_profile)
+ __aa_replace_profile(old_profile, new_profile);
+ if (rename_profile)
+ __aa_replace_profile(rename_profile, new_profile);
+ if (!(old_profile || rename_profile))
+ __add_new_profile(ns, policy, new_profile);
+ }
+ write_unlock(&ns->lock);
+
+out:
+ aa_put_namespace(ns);
+ aa_put_profile(rename_profile);
+ aa_put_profile(old_profile);
+ aa_put_profile(new_profile);
+ if (error)
+ return error;
+ return size;
+
+fail:
+ error = aa_audit_iface(&sa);
+ goto out;
+}
+
+/**
+ * aa_interface_remove_profiles - remove profile(s) from the system
+ * @fqname: name of the profile or namespace to remove
+ * @size: size of the name
+ *
+ * Remove a profile or sub namespace from the current namespace, so that
+ * they can not be found anymore and mark them as replaced by unconfined
+ *
+ * NOTE: removing confinement does not restore rlimits to preconfinemnet values
+ */
+ssize_t aa_interface_remove_profiles(char *fqname, size_t size)
+{
+ struct aa_namespace *root, *ns = NULL;
+ struct aa_profile *profile = NULL;
+ struct aa_audit_iface sa = {
+ .base.operation = "profile_remove",
+ .base.gfp_mask = GFP_ATOMIC,
+ };
+ const char *name = fqname;
+ int error;
+
+ /* check if loading policy is locked out */
+ if (aa_g_lock_policy) {
+ sa.base.info = "policy locked";
+ sa.base.error = -EACCES;
+ goto fail;
+ }
+
+ if (*fqname == 0) {
+ sa.base.info = "no profile specified";
+ sa.base.error = -ENOENT;
+ goto fail;
+ }
+
+ /* ref count held by cred */
+ root = aa_current_profile()->ns;
+
+ if (fqname[0] == ':') {
+ char *ns_name;
+ name = aa_split_fqname(fqname, &ns_name);
+ if (ns_name)
+ /* released below */
+ ns = aa_find_namespace(root, ns_name);
+ } else
+ /* released below */
+ ns = aa_get_namespace(root);
+
+ if (!ns) {
+ sa.base.info = "namespace does not exist";
+ sa.base.error = -ENOENT;
+ goto fail;
+ }
+
+ sa.name2 = ns->base.name;
+ write_lock(&ns->lock);
+ if (!name) {
+ /* remove namespace - can only happen if fqname[0] == ':' */
+ __aa_remove_namespace(ns);
+ } else {
+ /* remove profile */
+ profile = aa_get_profile(__aa_find_profile(&ns->base, name));
+ if (!profile) {
+ sa.name = name;
+ sa.base.error = -ENOENT;
+ sa.base.info = "profile does not exist";
+ goto fail_ns_lock;
+ }
+ sa.name = profile->base.hname;
+ __aa_profile_list_release(&profile->base.profiles);
+ __aa_replace_profile(profile, NULL);
+ }
+ write_unlock(&ns->lock);
+
+ /* don't fail removal if audit fails */
+ (void) aa_audit_iface(&sa);
+ aa_put_namespace(ns);
+ aa_put_profile(profile);
+ return size;
+
+fail_ns_lock:
+ write_unlock(&ns->lock);
+ aa_put_namespace(ns);
+
+fail:
+ error = aa_audit_iface(&sa);
+ return error;
+}
diff --git a/security/apparmor/sid.c b/security/apparmor/sid.c
new file mode 100644
index 0000000..ff55637
--- /dev/null
+++ b/security/apparmor/sid.c
@@ -0,0 +1,70 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor security identifier (sid) manipulation fns
+ *
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * 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.
+ *
+ *
+ * AppArmor allocates a unique sid for every profile loaded. If a profile
+ * is replaced it receive the sid of the profile it is replacing. Each sid
+ * is a u32 with the lower u16 being sids of system profiles and the
+ * upper u16 being user profile sids.
+ *
+ * The sid value of 0 is invalid for system sids and is used to indicate
+ * unconfined for user sids.
+ *
+ * A compound sid is a pair of user and system sids that is used to identify
+ * both profiles confining a task.
+ *
+ * Both system and user sids are globally unique with all users pulling
+ * from the same sid pool. User sid allocation is limited by the
+ * user controls, that can limit how many profiles are loaded by a user.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+
+#include "include/sid.h"
+
+/* global counter from which sids are allocated */
+static u16 global_sys_sid;
+static u16 global_usr_sid;
+static DEFINE_SPINLOCK(sid_lock);
+
+/* TODO FIXME: add sid to profile mapping, and sid recycling */
+
+/**
+ * aa_alloc_sid - allocate a new sid for a profile
+ * @is_usr: true if the new sid is a user based sid
+ */
+u32 aa_alloc_sid(int is_usr)
+{
+ u32 sid;
+
+ /*
+ * TODO FIXME: sid recycling - part of profile mapping table
+ */
+ spin_lock(&sid_lock);
+ if (is_usr)
+ sid = (++global_usr_sid) << 16;
+ else
+ sid = ++global_sys_sid;
+ spin_unlock(&sid_lock);
+ return sid;
+}
+
+/**
+ * aa_free_sid - free a sid
+ * @sid: sid to free
+ */
+void aa_free_sid(u32 sid)
+{
+ ; /* NOP ATM */
+}
--
1.6.6.1
--
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