blob: 7a9d4c8e2e39b6cb8eb5c6e685ffd6bd1a787c5b [file] [log] [blame]
/*
* 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 system 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 automatically generated learning profiles
*
* Namespace names may not start with / or @ and may not contain \0 or :
* Reserved namespace names
* user-XXXX - user defined profiles
*
* a // in a profile or namespace name indicates a hierarchical name with the
* name before the // being the parent and the name after the child.
*
* Profile and namespace hierarchies 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 hierarchy 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 // separators
* is referred 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/label.h"
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/policy_unpack.h"
#include "include/resource.h"
/* root profile namespace */
struct aa_namespace *root_ns;
/* Note: mode names must be unique in the first character because of
* modechrs used to print modes on compound labels on some interfaces
*/
const char *const aa_profile_mode_names[] = {
"enforce",
"complain",
"kill",
"unconfined",
};
/**
* hname_tail - find the last component of an hname
* @name: hname to find the base profile name component of (NOT NULL)
*
* Returns: the tail (base profile name) name component of an hname
*/
static const char *hname_tail(const char *hname)
{
char *split;
hname = strim((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 (NOT NULL)
* @prefix: prefix name if any is required. (MAYBE NULL)
* @name: name of the policy, init will make a copy of it (NOT NULL)
*
* Note: this fn creates a copy of strings passed in
*
* Returns: true if policy init successful
*/
static bool policy_init(struct aa_policy *policy, const char *prefix,
const char *name)
{
char *hname;
/* freed by policy_free */
if (prefix) {
hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3,
GFP_KERNEL);
if (hname)
sprintf(hname, "%s//%s", prefix, name);
} else {
hname = aa_str_alloc(strlen(name) + 1, GFP_KERNEL);
if (hname)
strcpy(hname, name);
}
if (!hname)
return 0;
policy->hname = hname;
/* base.name is a substring of fqname */
policy->name = (char *)hname_tail(policy->hname);
INIT_LIST_HEAD(&policy->list);
INIT_LIST_HEAD(&policy->profiles);
return 1;
}
/**
* policy_destroy - free the elements referenced by @policy
* @policy: policy that is to have its elements freed (NOT NULL)
*/
static void policy_destroy(struct aa_policy *policy)
{
/* still contains profiles -- invalid */
if (on_list_rcu(&policy->profiles)) {
AA_ERROR("%s: internal error, "
"policy '%s' still contains profiles\n",
__func__, policy->name);
BUG();
}
if (on_list_rcu(&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 */
aa_put_str(policy->hname);
}
/**
* __policy_find - find a policy by @name on a policy list
* @head: list to search (NOT NULL)
* @name: name to search for (NOT NULL)
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted 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_rcu(policy, head, list) {
if (!strcmp(policy->name, name))
return policy;
}
return NULL;
}
/**
* __policy_strn_find - find a policy that's name matches @len chars of @str
* @head: list to search (NOT NULL)
* @str: string to search for (NOT NULL)
* @len: length of match required
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted 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_rcu(policy, head, list) {
if (aa_strneq(policy->name, str, len))
return policy;
}
return NULL;
}
/*
* Routines for AppArmor namespaces
*/
const char *aa_hidden_ns_name = "---";
/**
* aa_ns_visible - test if @view is visible from @curr
* @curr: namespace to treat as the parent (NOT NULL)
* @view: namespace to test if visible from @curr (NOT NULL)
*
* Returns: true if @view is visible from @curr else false
*/
bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
{
if (curr == view)
return true;
for ( ; view; view = view->parent) {
if (view->parent == curr)
return true;
}
return false;
}
/**
* aa_na_name - Find the ns name to display for @view from @curr
* @curr - current namespace (NOT NULL)
* @view - namespace attempting to view (NOT NULL)
*
* Returns: name of @view visible from @curr
*/
const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
{
/* if view == curr then the namespace name isn't displayed */
if (curr == view)
return "";
if (aa_ns_visible(curr, view)) {
/* at this point if a ns is visible it is in a view ns
* thus the curr ns.hname is a prefix of its name.
* Only output the virtualized portion of the name
* Add + 2 to skip over // separating curr hname prefix
* from the visible tail of the views hname
*/
return view->base.hname + strlen(curr->base.hname) + 2;
} else
return aa_hidden_ns_name;
}
/**
* alloc_namespace - allocate, initialize and return a new namespace
* @prefix: parent namespace name (MAYBE NULL)
* @name: a preallocated name (NOT NULL)
*
* Returns: refcounted namespace or NULL on failure.
*/
static struct aa_namespace *alloc_namespace(const char *prefix,
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, prefix, name))
goto fail_ns;
INIT_LIST_HEAD(&ns->sub_ns);
mutex_init(&ns->lock);
/* released by free_namespace */
ns->unconfined = aa_alloc_profile("unconfined");
if (!ns->unconfined)
goto fail_unconfined;
ns->unconfined->label.replacedby = aa_alloc_replacedby(NULL);
if (!ns->unconfined->label.replacedby)
goto fail_replacedby;
ns->unconfined->label.flags |= FLAG_IX_ON_NAME_ERROR |
FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
ns->unconfined->mode = APPARMOR_UNCONFINED;
/* ns and ns->unconfined share ns->unconfined refcount */
ns->unconfined->ns = ns;
atomic_set(&ns->uniq_null, 0);
aa_labelset_init(&ns->labels);
return ns;
fail_replacedby:
aa_free_profile(ns->unconfined);
fail_unconfined:
kzfree(ns->base.hname);
fail_ns:
kzfree(ns);
return NULL;
}
/**
* aa_free_namespace - free a profile namespace
* @ns: the namespace to free (MAYBE NULL)
*
* Requires: All references to the namespace must have been put, if the
* namespace was referenced by a profile confining a task,
*/
void aa_free_namespace(struct aa_namespace *ns)
{
if (!ns)
return;
policy_destroy(&ns->base);
aa_labelset_destroy(&ns->labels);
aa_put_namespace(ns->parent);
ns->unconfined->ns = NULL;
aa_free_profile(ns->unconfined);
kzfree(ns);
}
/**
* __aa_findn_namespace - find a namespace on a list by @name
* @head: list to search for namespace on (NOT NULL)
* @name: name of namespace to look for (NOT NULL)
* @n: length of @name
* Returns: unrefcounted namespace
*
* Requires: rcu_read_lock be held
*/
static struct aa_namespace *__aa_findn_namespace(struct list_head *head,
const char *name, size_t n)
{
return (struct aa_namespace *)__policy_strn_find(head, name, n);
}
/**
* aa_find_namespace - look up a profile namespace on the namespace list
* @root: namespace to search in (NOT NULL)
* @name: name of namespace to find (NOT NULL)
* @n: length of @name
*
* Returns: a refcounted namespace on the list, or NULL if no namespace
* called @name exists.
*
* refcount released by caller
*/
struct aa_namespace *aa_findn_namespace(struct aa_namespace *root,
const char *name, size_t n)
{
struct aa_namespace *ns = NULL;
rcu_read_lock();
ns = aa_get_namespace(__aa_findn_namespace(&root->sub_ns, name, n));
rcu_read_unlock();
return ns;
}
/**
* aa_find_namespace - look up a profile namespace on the namespace list
* @root: namespace to search in (NOT NULL)
* @name: name of namespace to find (NOT NULL)
*
* Returns: a refcounted 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)
{
return aa_findn_namespace(root, name, strlen(name));
}
/**
* aa_prepare_namespace - find an existing or create a new namespace of @name
* @name: the namespace to find or add (MAYBE NULL)
*
* Returns: 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 = labels_ns(aa_current_label());
mutex_lock(&root->lock);
/* if name isn't specified the profile is loaded to the current ns */
if (!name) {
/* released by caller */
ns = aa_get_namespace(root);
goto out;
}
/* try and find the specified ns and if it doesn't exist create it */
/* released by caller */
ns = aa_get_namespace(__aa_findn_namespace(&root->sub_ns, name,
strlen(name)));
if (!ns) {
ns = alloc_namespace(root->base.hname, name);
if (!ns)
goto out;
if (__aa_fs_namespace_mkdir(ns, ns_subns_dir(root), name)) {
AA_ERROR("Failed to create interface for ns %s\n",
ns->base.name);
aa_free_namespace(ns);
ns = NULL;
goto out;
}
ns->parent = aa_get_namespace(root);
ns->level = root->level + 1;
list_add_rcu(&ns->base.list, &root->sub_ns);
/* add list ref */
aa_get_namespace(ns);
}
out:
mutex_unlock(&root->lock);
/* return ref */
return ns;
}
/**
* __add_profile - add a profiles to list and label tree
* @list: list to add it to (NOT NULL)
* @profile: the profile to add (NOT NULL)
*
* refcount @profile, should be put by __list_remove_profile
*
* Requires: namespace lock be held, or list not be shared
*/
static void __add_profile(struct list_head *list, struct aa_profile *profile)
{
struct aa_label *l;
AA_BUG(!list);
AA_BUG(!profile);
AA_BUG(!profile->ns);
AA_BUG(!mutex_is_locked(&profile->ns->lock));
list_add_rcu(&profile->base.list, list);
/* get list reference */
aa_get_profile(profile);
l = aa_label_insert(&profile->ns->labels, &profile->label);
AA_BUG(l != &profile->label);
aa_put_label(l);
}
/**
* __list_remove_profile - remove a profile from the list it is on
* @profile: the profile to remove (NOT NULL)
*
* remove a profile from the list, warning generally removal should
* be done with __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 __list_remove_profile(struct aa_profile *profile)
{
AA_BUG(!profile);
AA_BUG(!profile->ns);
AA_BUG(!mutex_is_locked(&profile->ns->lock));
list_del_rcu(&profile->base.list);
aa_put_profile(profile);
}
static void __profile_list_release(struct list_head *head);
/**
* __remove_profile - remove old profile, and children
* @profile: profile to be replaced (NOT NULL)
*
* Requires: namespace list lock be held, or list not be shared
*/
static void __remove_profile(struct aa_profile *profile)
{
AA_BUG(!profile);
AA_BUG(!profile->ns);
AA_BUG(!mutex_is_locked(&profile->ns->lock));
/* release any children lists first */
__profile_list_release(&profile->base.profiles);
/* released by free_profile */
aa_label_remove(&profile->ns->labels, &profile->label);
__aa_update_replacedby(&profile->label,
&profile->ns->unconfined->label);
__aa_fs_profile_rmdir(profile);
__list_remove_profile(profile);
}
/**
* __profile_list_release - remove all profiles on the list and put refs
* @head: list of profiles (NOT NULL)
*
* Requires: namespace lock be held
*/
static void __profile_list_release(struct list_head *head)
{
struct aa_profile *profile, *tmp;
list_for_each_entry_safe(profile, tmp, head, base.list)
__remove_profile(profile);
}
static void __ns_list_release(struct list_head *head);
/**
* destroy_namespace - remove everything contained by @ns
* @ns: namespace to have it contents removed (NOT NULL)
*/
static void destroy_namespace(struct aa_namespace *ns)
{
if (!ns)
return;
mutex_lock(&ns->lock);
/* release all profiles in this namespace */
__profile_list_release(&ns->base.profiles);
/* release all sub namespaces */
__ns_list_release(&ns->sub_ns);
if (ns->parent)
__aa_update_replacedby(&ns->unconfined->label,
&ns->parent->unconfined->label);
__aa_fs_namespace_rmdir(ns);
mutex_unlock(&ns->lock);
}
/**
* __remove_namespace - remove a namespace and all its children
* @ns: namespace to be removed (NOT NULL)
*
* Requires: ns->parent->lock be held and ns removed from parent.
*/
static void __remove_namespace(struct aa_namespace *ns)
{
/* remove ns from namespace list */
list_del_rcu(&ns->base.list);
destroy_namespace(ns);
aa_put_namespace(ns);
}
/**
* __ns_list_release - remove all profile namespaces on the list put refs
* @head: list of profile namespaces (NOT NULL)
*
* Requires: namespace lock be held
*/
static void __ns_list_release(struct list_head *head)
{
struct aa_namespace *ns, *tmp;
list_for_each_entry_safe(ns, tmp, head, base.list)
__remove_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 = alloc_namespace(NULL, "root");
if (!root_ns)
return -ENOMEM;
return 0;
}
/**
* aa_free_root_ns - free the root profile namespace
*/
void __init aa_free_root_ns(void)
{
struct aa_namespace *ns = root_ns;
root_ns = NULL;
destroy_namespace(ns);
aa_put_namespace(ns);
}
/**
* aa_free_profile - free a profile
* @profile: the profile to free (MAYBE NULL)
*
* 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, free_profile() will
* be called from an rcu callback routine, so we must not sleep here.
*/
void aa_free_profile(struct aa_profile *profile)
{
AA_DEBUG("%s(%p)\n", __func__, profile);
if (!profile)
return;
/* free children profiles */
policy_destroy(&profile->base);
aa_put_profile(rcu_access_pointer(profile->parent));
aa_put_namespace(profile->ns);
kzfree(profile->rename);
aa_free_file_rules(&profile->file);
aa_free_cap_rules(&profile->caps);
aa_free_net_rules(&profile->net);
aa_free_rlimit_rules(&profile->rlimits);
kzfree(profile->dirname);
aa_put_dfa(profile->xmatch);
aa_put_dfa(profile->policy.dfa);
kzfree(profile->hash);
kzfree(profile);
}
/**
* aa_alloc_profile - allocate, initialize and return a new profile
* @hname: name of the profile (NOT NULL)
*
* Returns: refcount profile or NULL on failure
*/
struct aa_profile *aa_alloc_profile(const char *hname)
{
struct aa_profile *profile;
/* freed by free_profile - usually through aa_put_profile */
profile = kzalloc(sizeof(*profile), GFP_KERNEL);
if (!profile)
return NULL;
if (!policy_init(&profile->base, NULL, hname))
goto fail;
if (!aa_label_init(&profile->label, 1))
goto fail;
profile->label.hname = profile->base.hname;
profile->label.flags |= FLAG_PROFILE;
profile->label.ent[0] = profile;
/* refcount released by caller */
return profile;
fail:
kzfree(profile);
return NULL;
}
/**
* aa_new_null_profile - create a new null-X learning profile
* @parent: profile that caused this profile to be created (NOT NULL)
* @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-<uniq>.
*
* 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.
*
* Returns: new refcounted profile else NULL on failure
*/
struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
{
struct aa_profile *profile = NULL;
char *name;
int uniq = atomic_inc_return(&parent->ns->uniq_null);
/* 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, uniq);
profile = aa_alloc_profile(name);
kfree(name);
if (!profile)
goto fail;
profile->label.replacedby = aa_alloc_replacedby(NULL);
if (!profile->label.replacedby)
goto fail;
profile->mode = APPARMOR_COMPLAIN;
profile->label.flags |= FLAG_NULL;
if (hat)
profile->label.flags |= FLAG_HAT;
/* released on free_profile */
rcu_assign_pointer(profile->parent, aa_get_profile(parent));
profile->ns = aa_get_namespace(parent->ns);
mutex_lock(&profile->ns->lock);
__add_profile(&parent->base.profiles, profile);
mutex_unlock(&profile->ns->lock);
/* refcount released by caller */
return profile;
fail:
aa_free_profile(profile);
return NULL;
}
/**
* aa_setup_default_label - create the initial default label
*/
struct aa_label *aa_setup_default_label(void)
{
struct aa_profile *profile = aa_alloc_profile("default");
if (!profile)
return NULL;
/* the default profile pretends to be unconfined until it is replaced */
profile->label.flags |= FLAG_IX_ON_NAME_ERROR | FLAG_UNCONFINED;
profile->mode = APPARMOR_UNCONFINED;
profile->ns = aa_get_namespace(root_ns);
/* replacedby being set needed by fs interface */
profile->label.replacedby = aa_alloc_replacedby(&profile->label);
if (!profile->label.replacedby) {
aa_free_profile(profile);
return NULL;
}
__add_profile(&root_ns->base.profiles, profile);
return &profile->label;
}
/* TODO: profile accounting - setup in remove */
/**
* __find_child - find a profile on @head list with a name matching @name
* @head: list to search (NOT NULL)
* @name: name of profile (NOT NULL)
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted profile ptr, or NULL if not found
*/
static struct aa_profile *__find_child(struct list_head *head, const char *name)
{
return (struct aa_profile *)__policy_find(head, name);
}
/**
* __strn_find_child - find a profile on @head list using substring of @name
* @head: list to search (NOT NULL)
* @name: name of profile (NOT NULL)
* @len: length of @name substring to match
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted profile ptr, or NULL if not found
*/
static struct aa_profile *__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 (NOT NULL)
* @name: profile name to search for (NOT NULL)
*
* Returns: a refcounted profile or NULL if not found
*/
struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
{
struct aa_profile *profile;
rcu_read_lock();
profile = aa_get_profile(__find_child(&parent->base.profiles, name));
rcu_read_unlock();
/* refcount released by caller */
return profile;
}
/**
* __lookup_parent - lookup the parent of a profile of name @hname
* @ns: namespace to lookup profile in (NOT NULL)
* @hname: hierarchical profile name to find parent of (NOT NULL)
*
* 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: rcu_read_lock be held
*
* Returns: unrefcounted policy or NULL if not found
*/
static struct aa_policy *__lookup_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 = __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;
}
/**
* __lookupn_profile - lookup the profile matching @hname
* @base: base list to start looking up profile name from (NOT NULL)
* @hname: hierarchical profile name (NOT NULL)
* @n: length of @hname
*
* Requires: rcu_read_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 *__lookupn_profile(struct aa_policy *base,
const char *hname, size_t n)
{
struct aa_profile *profile = NULL;
const char *split, *name = hname;
for (split = strstr(hname, "//"); split && (split - hname <= n);) {
profile = __strn_find_child(&base->profiles, name,
split - name);
if (!profile)
return NULL;
base = &profile->base;
name = split + 2;
split = strstr(name, "//");
}
if (name - hname <= n)
return __strn_find_child(&base->profiles, name,
n - (name - hname));
return NULL;
}
static struct aa_profile *__lookup_profile(struct aa_policy *base,
const char *hname)
{
return __lookupn_profile(base, hname, strlen(hname));
}
/**
* aa_lookup_profile - find a profile by its full or partial name
* @ns: the namespace to start from (NOT NULL)
* @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL)
* @n: size of @hname
*
* Returns: refcounted profile or NULL if not found
*/
struct aa_profile *aa_lookupn_profile(struct aa_namespace *ns,
const char *hname, size_t n)
{
struct aa_profile *profile;
rcu_read_lock();
do {
profile = __lookupn_profile(&ns->base, hname, n);
} while (profile && !aa_get_profile_not0(profile));
rcu_read_unlock();
/* the unconfined profile is not in the regular profile list */
if (!profile && strncmp(hname, "unconfined", n) == 0)
profile = aa_get_newest_profile(ns->unconfined);
/* refcount released by caller */
return profile;
}
struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
{
return aa_lookupn_profile(ns, hname, strlen(hname));
}
struct aa_profile *aa_fqlookupn_profile(struct aa_label *base, char *fqname,
size_t n)
{
struct aa_profile *profile;
struct aa_namespace *ns;
char *name, *ns_name;
size_t ns_len;
name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
if (ns_name) {
ns = aa_findn_namespace(labels_ns(base), ns_name, ns_len);
if (!ns)
return NULL;
} else
ns = aa_get_namespace(labels_ns(base));
profile = aa_lookupn_profile(ns, name, n - (name - fqname));
aa_put_namespace(ns);
return profile;
}
/**
* replacement_allowed - test to see if replacement is allowed
* @profile: profile to test if it can be replaced (MAYBE NULL)
* @noreplace: true if replacement shouldn't be allowed but addition is okay
* @info: Returns - info about why replacement failed (NOT NULL)
*
* Returns: %0 if replacement allowed else error code
*/
static int replacement_allowed(struct aa_profile *profile, int noreplace,
const char **info)
{
if (profile) {
if (profile->label.flags & FLAG_IMMUTIBLE) {
*info = "cannot replace immutible profile";
return -EPERM;
} else if (noreplace) {
*info = "profile already exists";
return -EEXIST;
}
}
return 0;
}
/**
* aa_audit_policy - Do auditing of policy changes
* @op: policy operation being performed
* @name: name of profile being manipulated (NOT NULL)
* @info: any extra information to be audited (MAYBE NULL)
* @error: error code
*
* Returns: the error to be returned after audit is done
*/
static int audit_policy(int op, const char *name, const char *info,
int error)
{
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);
// aad(&sa)->op = op;
aad(&sa)->name = name;
aad(&sa)->info = info;
aad(&sa)->error = error;
return aa_audit(AUDIT_APPARMOR_STATUS,
labels_profile(aa_current_raw_label()), &sa, NULL);
}
/**
* aa_may_manage_policy - can the current task manage policy
* @op: the policy manipulation operation being done
*
* Returns: true if the task is allowed to manipulate policy
*/
bool aa_may_manage_policy(int op)
{
/* check if loading policy is locked out */
if (aa_g_lock_policy) {
audit_policy(op, NULL, "policy_locked", -EACCES);
return 0;
}
if (!capable(CAP_MAC_ADMIN)) {
audit_policy(op, NULL, "not policy admin", -EACCES);
return 0;
}
return 1;
}
static struct aa_profile *__list_lookup_parent(struct list_head *lh,
struct aa_profile *profile)
{
const char *base = hname_tail(profile->base.hname);
long len = base - profile->base.hname;
struct aa_load_ent *ent;
/* parent won't have trailing // so remove from len */
if (len <= 2)
return NULL;
len -= 2;
list_for_each_entry(ent, lh, list) {
if (ent->new == profile)
continue;
if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
0 && ent->new->base.hname[len] == 0)
return ent->new;
}
return NULL;
}
/**
* __replace_profile - replace @old with @new on a list
* @old: profile to be replaced (NOT NULL)
* @new: profile to replace @old with (NOT NULL)
* @share_replacedby: transfer @old->replacedby to @new
*
* Will duplicate and refcount elements that @new inherits from @old
* and will inherit @old children.
*
* refcount @new for list, put @old list refcount
*
* Requires: namespace list lock be held, or list not be shared
*/
static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
bool share_replacedby)
{
struct aa_profile *child, *tmp;
if (!list_empty(&old->base.profiles)) {
LIST_HEAD(lh);
list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
list_for_each_entry_safe(child, tmp, &lh, base.list) {
struct aa_profile *p;
list_del_init(&child->base.list);
p = __find_child(&new->base.profiles, child->base.name);
if (p) {
/* @p replaces @child */
__replace_profile(child, p, share_replacedby);
continue;
}
/* inherit @child and its children */
/* TODO: update hname of inherited children */
/* list refcount transferred to @new */
p = aa_deref_parent(child);
rcu_assign_pointer(child->parent, aa_get_profile(new));
list_add_rcu(&child->base.list, &new->base.profiles);
aa_put_profile(p);
}
}
if (!rcu_access_pointer(new->parent)) {
struct aa_profile *parent = aa_deref_parent(old);
rcu_assign_pointer(new->parent, aa_get_profile(parent));
}
__aa_update_replacedby(&old->label, &new->label);
if (share_replacedby)
new->label.replacedby = aa_get_replacedby(old->label.replacedby);
else if (!rcu_access_pointer(new->label.replacedby->label))
/* aafs interface uses replacedby */
rcu_assign_pointer(new->label.replacedby->label,
aa_get_label(&new->label));
__aa_fs_profile_migrate_dents(old, new);
if (list_empty(&new->base.list)) {
/* new is not on a list already */
list_replace_rcu(&old->base.list, &new->base.list);
aa_get_profile(new);
aa_put_profile(old);
} else
__list_remove_profile(old);
}
/**
* __lookup_replace - lookup replacement information for a profile
* @ns - namespace the lookup occurs in
* @hname - name of profile to lookup
* @noreplace - true if not replacing an existing profile
* @p - Returns: profile to be replaced
* @info - Returns: info string on why lookup failed
*
* Returns: profile to replace (no ref) on success else ptr error
*/
static int __lookup_replace(struct aa_namespace *ns, const char *hname,
bool noreplace, struct aa_profile **p,
const char **info)
{
*p = aa_get_profile(__lookup_profile(&ns->base, hname));
if (*p) {
int error = replacement_allowed(*p, noreplace, info);
if (error) {
*info = "profile can not be replaced";
return error;
}
}
return 0;
}
static void share_name(struct aa_profile *old, struct aa_profile *new)
{
aa_put_str(new->base.hname);
aa_get_str(old->base.hname);
new->base.hname = old->base.hname;
new->base.name = old->base.name;
new->label.hname = old->label.hname;
}
/* Update to newest version of parent after previous replacements
* Returns: unrefcount newest version of parent
*/
static struct aa_profile *update_to_newest_parent(struct aa_profile *new)
{
struct aa_profile *parent, *newest;
parent = rcu_dereference_protected(new->parent,
mutex_is_locked(&new->ns->lock));
newest = aa_get_newest_profile(parent);
/* parent replaced in this atomic set? */
if (newest != parent) {
aa_put_profile(parent);
rcu_assign_pointer(new->parent, newest);
} else
aa_put_profile(newest);
return newest;
}
/**
* aa_replace_profiles - replace profile(s) on the profile list
* @udata: serialized data stream (NOT NULL)
* @size: size of the serialized data stream
* @noreplace: 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.
*
* Returns: size of data consumed else error code on failure.
*/
ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
{
const char *ns_name, *name = NULL, *info = NULL;
struct aa_namespace *ns = NULL;
struct aa_load_ent *ent, *tmp;
int op = OP_PROF_REPL;
ssize_t error;
LIST_HEAD(lh);
/* released below */
error = aa_unpack(udata, size, &lh, &ns_name);
if (error)
goto out;
/* released below */
ns = aa_prepare_namespace(ns_name);
if (!ns) {
info = "failed to prepare namespace";
error = -ENOMEM;
name = ns_name;
goto fail;
}
mutex_lock(&ns->lock);
/* setup parent and ns info */
list_for_each_entry(ent, &lh, list) {
struct aa_policy *policy;
name = ent->new->base.hname;
error = __lookup_replace(ns, ent->new->base.hname, noreplace,
&ent->old, &info);
if (error)
goto fail_lock;
if (ent->new->rename) {
error = __lookup_replace(ns, ent->new->rename,
noreplace, &ent->rename,
&info);
if (error)
goto fail_lock;
}
/* released when @new is freed */
ent->new->ns = aa_get_namespace(ns);
if (ent->old || ent->rename)
continue;
/* no ref on policy only use inside lock */
policy = __lookup_parent(ns, ent->new->base.hname);
if (!policy) {
struct aa_profile *p;
p = __list_lookup_parent(&lh, ent->new);
if (!p) {
error = -ENOENT;
info = "parent does not exist";
name = ent->new->base.hname;
goto fail_lock;
}
rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
} else if (policy != &ns->base) {
/* released on profile replacement or free_profile */
struct aa_profile *p = (struct aa_profile *) policy;
rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
}
}
/* create new fs entries for introspection if needed */
list_for_each_entry(ent, &lh, list) {
struct aa_replacedby *r;
if (ent->old) {
/* inherit old interface files */
/* if (ent->rename)
TODO: support rename */
/* } else if (ent->rename) {
TODO: support rename */
} else {
struct dentry *parent;
r = aa_alloc_replacedby(NULL);
if (!r) {
info = "failed to create";
error = -ENOMEM;
goto fail_lock;
}
ent->new->label.replacedby = r;
if (rcu_access_pointer(ent->new->parent)) {
struct aa_profile *p;
p = aa_deref_parent(ent->new);
parent = prof_child_dir(p);
} else
parent = ns_subprofs_dir(ent->new->ns);
error = __aa_fs_profile_mkdir(ent->new, parent);
}
if (error) {
info = "failed to create";
goto fail_lock;
}
}
/* Done with checks that may fail - do actual replacement */
list_for_each_entry_safe(ent, tmp, &lh, list) {
list_del_init(&ent->list);
op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
audit_policy(op, ent->new->base.name, NULL, error);
if (ent->old) {
share_name(ent->old, ent->new);
__replace_profile(ent->old, ent->new, 1);
aa_label_replace(&ns->labels, &ent->old->label,
&ent->new->label);
if (ent->rename) {
/* aafs interface uses replacedby */
rcu_assign_pointer(ent->new->label.replacedby->label,
aa_get_label(&ent->new->label));
__replace_profile(ent->rename, ent->new, 0);
}
} else if (ent->rename) {
/* aafs interface uses replacedby */
rcu_assign_pointer(ent->new->label.replacedby->label,
aa_get_label(&ent->new->label));
} else {
struct list_head *lh;
if (rcu_access_pointer(ent->new->parent)) {
struct aa_profile *parent;
parent = update_to_newest_parent(ent->new);
lh = &parent->base.profiles;
} else
lh = &ns->base.profiles;
/* aafs interface uses replacedby */
rcu_assign_pointer(ent->new->label.replacedby->label,
aa_get_label(&ent->new->label));
__add_profile(lh, ent->new);
}
aa_load_ent_free(ent);
}
__aa_labelset_update_all(ns);
mutex_unlock(&ns->lock);
out:
aa_put_namespace(ns);
if (error)
return error;
return size;
fail_lock:
mutex_unlock(&ns->lock);
fail:
error = audit_policy(op, name, info, error);
list_for_each_entry_safe(ent, tmp, &lh, list) {
list_del_init(&ent->list);
aa_load_ent_free(ent);
}
goto out;
}
/**
* aa_remove_profiles - remove profile(s) from the system
* @fqname: name of the profile or namespace to remove (NOT NULL)
* @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
*
* Returns: size of data consume else error code if fails
*/
ssize_t aa_remove_profiles(char *fqname, size_t size)
{
struct aa_namespace *root, *ns = NULL;
struct aa_profile *profile = NULL;
const char *name = fqname, *info = NULL;
ssize_t error = 0;
if (*fqname == 0) {
info = "no profile specified";
error = -ENOENT;
goto fail;
}
root = labels_ns(aa_current_label());
if (fqname[0] == ':') {
char *ns_name;
name = aa_split_fqname(fqname, &ns_name);
/* released below */
ns = aa_find_namespace(root, ns_name);
if (!ns) {
info = "namespace does not exist";
error = -ENOENT;
goto fail;
}
} else
/* released below */
ns = aa_get_namespace(root);
if (!name) {
/* remove namespace - can only happen if fqname[0] == ':' */
mutex_lock(&ns->parent->lock);
__remove_namespace(ns);
mutex_unlock(&ns->parent->lock);
} else {
/* remove profile */
mutex_lock(&ns->lock);
profile = aa_get_profile(__lookup_profile(&ns->base, name));
if (!profile) {
error = -ENOENT;
info = "profile does not exist";
goto fail_ns_lock;
}
name = profile->base.hname;
__remove_profile(profile);
__aa_labelset_update_all(ns);
mutex_unlock(&ns->lock);
}
/* don't fail removal if audit fails */
(void) audit_policy(OP_PROF_RM, name, info, error);
aa_put_namespace(ns);
aa_put_profile(profile);
return size;
fail_ns_lock:
mutex_unlock(&ns->lock);
aa_put_namespace(ns);
fail:
(void) audit_policy(OP_PROF_RM, name, info, error);
return error;
}