- 根目录:
- security
- apparmor
- policy.c
/*
* 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/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 *const profile_mode_names[] = {
"enforce",
"complain",
"kill",
};
/**
* 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)
{
/* freed by policy_free */
if (prefix) {
policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
GFP_KERNEL);
if (policy->hname)
sprintf(policy->hname, "%s//%s", prefix, name);
} else
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 (NOT NULL)
*/
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 (NOT NULL)
* @name: name to search for (NOT NULL)
*
* Requires: correct locks for the @head list 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(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: correct locks for the @head list 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(policy, head, list) {
if (aa_strneq(policy->name, str, len))
return policy;
}
return NULL;
}
/*
* Routines for AppArmor namespaces
*/
static const char *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 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);
rwlock_init(&ns->lock);
/* released by free_namespace */
ns->unconfined = aa_alloc_profile("unconfined");
if (!ns->unconfined)
goto fail_unconfined;
ns->unconfined->sid = aa_alloc_sid();
ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
PFLAG_IMMUTABLE;
/*
* released by free_namespace, however __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.hname);
fail_ns:
kzfree(ns);
return NULL;
}
/**
* 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,
*/
static void 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 (NOT NULL)
*/
void aa_free_namespace_kref(struct kref *kref)
{
free_namespace(container_of(kref, struct aa_namespace, base.count));
}
/**
* __aa_find_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)
*
* Returns: 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 (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)
{
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 (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 = aa_current_profile()->ns;
write_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_find_namespace(&root->sub_ns, name));
if (!ns) {
/* namespace not found */
struct aa_namespace *new_ns;
write_unlock(&root->lock);
new_ns = alloc_namespace(root->base.hname, 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 */
free_namespace(new_ns);
/* get reference on namespace */
aa_get_namespace(ns);
}
}
out:
write_unlock(&root->lock);
/* return ref */
return ns;
}
/**
* __list_add_profile - add a profile to a list
* @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 __list_add_profile(struct list_head *list,
struct aa_profile *profile)
{
list_add(&profile->base.list, list);
/* get list reference */
aa_get_profile(profile);
}
/**
* __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)
{
list_del_init(&profile->base.list);
if (!(profile->flags & PFLAG_NO_LIST_REF))
/* release list reference */
aa_put_profile(profile);
}
/**
* __replace_profile - replace @old with @new on a list
* @old: profile to be replaced (NOT NULL)
* @new: profile to replace @old with (NOT NULL)
*
* 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)
{
struct aa_policy *policy;
struct aa_profile *child, *tmp;
if (old->parent)
policy = &old->parent->base;
else
policy = &old->ns->base;
/* released when @new is freed */
new->parent = aa_get_profile(old->parent);
new->ns = aa_get_namespace(old->ns);
new->sid = old->sid;
__list_add_profile(&policy->profiles, new);
/* 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 transferred to @new*/
list_move(&child->base.list, &new->base.profiles);
}
/* released by free_profile */
old->replacedby = aa_get_profile(new);
__list_remove_profile(old);
}
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)
{
/* release any children lists first */
__profile_list_release(&profile->base.profiles);
/* released by free_profile */
profile->replacedby = aa_get_profile(profile->ns->unconfined);
__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;
write_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);
write_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)
{
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);
destroy_namespace(ns);
/* release original ns->unconfined ref */
aa_put_profile(unconfined);
/* release ns->base.list ref, from removal above */
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_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)) {
kzfree(profile);
return NULL;
}
/* refcount released by caller */
return profile;
}
/**
* aa_new_null_profile - create a new null-X learning profile
* : 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-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.
*
* 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;
u32 sid = aa_alloc_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 = sid;
profile->mode = APPARMOR_COMPLAIN;
profile->flags = PFLAG_NULL;
if (hat)
profile->flags |= PFLAG_HAT;
/* released on free_profile */
profile->parent = aa_get_profile(parent);
profile->ns = aa_get_namespace(parent->ns);
write_lock(&profile->ns->lock);
__list_add_profile(&parent->base.profiles, profile);
write_unlock(&profile->ns->lock);
/* refcount released by caller */
return profile;
fail:
aa_free_sid(sid);
return NULL;
}
/**
* 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.
*/
static void 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);
kzfree(profile->rename);
aa_free_file_rules(&profile->file);
aa_free_cap_rules(&profile->caps);
aa_free_rlimit_rules(&profile->rlimits);
aa_free_sid(profile->sid);
aa_put_dfa(profile->xmatch);
aa_put_dfa(profile->policy.dfa);
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 (NOT NULL)
*/
void aa_free_profile_kref(struct kref *kref)
{
struct aa_profile *p = container_of(kref, struct aa_profile,
base.count);
free_profile(p);
}
/* 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: ns lock protecting list 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: ns lock protecting list 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
* : 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;
read_lock(&parent->ns->lock);
profile = aa_get_profile(__find_child(&parent->base.profiles, name));
read_unlock(&parent->ns->lock);
/* 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: ns->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;
}
/**
* __lookup_profile - lookup the profile matching @hname
* @base: base list to start looking up profile name from (NOT NULL)
* @hname: hierarchical profile name (NOT NULL)
*
* 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 *__lookup_profile(struct aa_policy *base,
const char *hname)
{
struct aa_profile *profile = NULL;
char *split;
for (split = strstr(hname, "//"); split;) {
profile = __strn_find_child(&base->profiles, hname,
split - hname);
if (!profile)
return NULL;
base = &profile->base;
hname = split + 2;
split = strstr(hname, "//");
}
profile = __find_child(&base->profiles, hname);
return profile;
}
/**
* 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)
*
* Returns: refcounted profile or NULL if not found
*/
struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
{
struct aa_profile *profile;
read_lock(&ns->lock);
profile = aa_get_profile(__lookup_profile(&ns->base, hname));
read_unlock(&ns->lock);
/* refcount released by caller */
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->flags & PFLAG_IMMUTABLE) {
*info = "cannot replace immutible profile";
return -EPERM;
} else if (noreplace) {
*info = "profile already exists";
return -EEXIST;
}
}
return 0;
}
/**
* __add_new_profile - simple wrapper around __list_add_profile
* @ns: namespace that profile is being added to (NOT NULL)
* @policy: the policy container to add the profile to (NOT NULL)
* @profile: profile to add (NOT NULL)
*
* 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 free_profile */
profile->parent = aa_get_profile((struct aa_profile *) policy);
__list_add_profile(&policy->profiles, profile);
/* released on free_profile */
profile->sid = aa_alloc_sid();
profile->ns = aa_get_namespace(ns);
}
/**
* aa_audit_policy - Do auditing of policy changes
* @op: policy operation being performed
* @gfp: memory allocation flags
* @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, gfp_t gfp, const char *name, const char *info,
int error)
{
struct common_audit_data sa;
struct apparmor_audit_data aad = {0,};
COMMON_AUDIT_DATA_INIT(&sa, NONE);
sa.aad = &aad;
aad.op = op;
aad.name = name;
aad.info = info;
aad.error = error;
return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
&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, GFP_KERNEL, NULL, "policy_locked", -EACCES);
return 0;
}
if (!capable(CAP_MAC_ADMIN)) {
audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
return 0;
}
return 1;
}
/**
* 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)
{
struct aa_policy *policy;
struct aa_profile *old_profile = NULL, *new_profile = NULL;
struct aa_profile *rename_profile = NULL;
struct aa_namespace *ns = NULL;
const char *ns_name, *name = NULL, *info = NULL;
int op = OP_PROF_REPL;
ssize_t error;
/* released below */
new_profile = aa_unpack(udata, size, &ns_name);
if (IS_ERR(new_profile)) {
error = PTR_ERR(new_profile);
new_profile = NULL;
goto fail;
}
/* released below */
ns = aa_prepare_namespace(ns_name);
if (!ns) {
info = "failed to prepare namespace";
error = -ENOMEM;
name = ns_name;
goto fail;
}
name = new_profile->base.hname;
write_lock(&ns->lock);
/* no ref on policy only use inside lock */
policy = __lookup_parent(ns, new_profile->base.hname);
if (!policy) {
info = "parent does not exist";
error = -ENOENT;
goto audit;
}
old_profile = __find_child(&policy->profiles, new_profile->base.name);
/* released below */
aa_get_profile(old_profile);
if (new_profile->rename) {
rename_profile = __lookup_profile(&ns->base,
new_profile->rename);
/* released below */
aa_get_profile(rename_profile);
if (!rename_profile) {
info = "profile to rename does not exist";
name = new_profile->rename;
error = -ENOENT;
goto audit;
}
}
error = replacement_allowed(old_profile, noreplace, &info);
if (error)
goto audit;
error = replacement_allowed(rename_profile, noreplace, &info);
if (error)
goto audit;
audit:
if (!old_profile && !rename_profile)
op = OP_PROF_LOAD;
error = audit_policy(op, GFP_ATOMIC, name, info, error);
if (!error) {
if (rename_profile)
__replace_profile(rename_profile, new_profile);
if (old_profile) {
/* when there are both rename and old profiles
* inherit old profiles sid
*/
if (rename_profile)
aa_free_sid(new_profile->sid);
__replace_profile(old_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 = audit_policy(op, GFP_KERNEL, name, info, error);
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 = 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);
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] == ':' */
write_lock(&ns->parent->lock);
__remove_namespace(ns);
write_unlock(&ns->parent->lock);
} else {
/* remove profile */
write_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);
write_unlock(&ns->lock);
}
/* don't fail removal if audit fails */
(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
aa_put_namespace(ns);
aa_put_profile(profile);
return size;
fail_ns_lock:
write_unlock(&ns->lock);
aa_put_namespace(ns);
fail:
(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
return error;
}