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246c3fb16b
policy->name is a substring of policy->hname, if prefix is not NULL, it will allocted strlen(prefix) + strlen(name) + 3 bytes to policy->hname in policy_init(). use kzfree(ns->base.name) will casue memory leak if alloc_namespace() failed. Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <jmorris@namei.org>
1187 lines
32 KiB
C
1187 lines
32 KiB
C
/*
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* AppArmor security module
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*
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* This file contains AppArmor policy manipulation functions
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*
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* Copyright (C) 1998-2008 Novell/SUSE
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* Copyright 2009-2010 Canonical Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*
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*
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* AppArmor policy is based around profiles, which contain the rules a
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* task is confined by. Every task in the system has a profile attached
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* to it determined either by matching "unconfined" tasks against the
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* visible set of profiles or by following a profiles attachment rules.
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*
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* Each profile exists in a profile namespace which is a container of
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* visible profiles. Each namespace contains a special "unconfined" profile,
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* which doesn't enforce any confinement on a task beyond DAC.
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*
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* Namespace and profile names can be written together in either
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* of two syntaxes.
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* :namespace:profile - used by kernel interfaces for easy detection
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* namespace://profile - used by policy
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*
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* Profile names can not start with : or @ or ^ and may not contain \0
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*
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* Reserved profile names
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* unconfined - special automatically generated unconfined profile
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* inherit - special name to indicate profile inheritance
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* null-XXXX-YYYY - special automatically generated learning profiles
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*
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* Namespace names may not start with / or @ and may not contain \0 or :
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* Reserved namespace names
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* user-XXXX - user defined profiles
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*
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* a // in a profile or namespace name indicates a hierarchical name with the
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* name before the // being the parent and the name after the child.
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*
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* Profile and namespace hierarchies serve two different but similar purposes.
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* The namespace contains the set of visible profiles that are considered
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* for attachment. The hierarchy of namespaces allows for virtualizing
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* the namespace so that for example a chroot can have its own set of profiles
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* which may define some local user namespaces.
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* The profile hierarchy severs two distinct purposes,
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* - it allows for sub profiles or hats, which allows an application to run
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* subprograms under its own profile with different restriction than it
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* self, and not have it use the system profile.
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* eg. if a mail program starts an editor, the policy might make the
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* restrictions tighter on the editor tighter than the mail program,
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* and definitely different than general editor restrictions
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* - it allows for binary hierarchy of profiles, so that execution history
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* is preserved. This feature isn't exploited by AppArmor reference policy
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* but is allowed. NOTE: this is currently suboptimal because profile
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* aliasing is not currently implemented so that a profile for each
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* level must be defined.
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* eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
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* from /bin/bash
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*
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* A profile or namespace name that can contain one or more // separators
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* is referred to as an hname (hierarchical).
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* eg. /bin/bash//bin/ls
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*
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* An fqname is a name that may contain both namespace and profile hnames.
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* eg. :ns:/bin/bash//bin/ls
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*
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* NOTES:
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* - locking of profile lists is currently fairly coarse. All profile
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* lists within a namespace use the namespace lock.
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* FIXME: move profile lists to using rcu_lists
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*/
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include "include/apparmor.h"
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#include "include/capability.h"
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#include "include/context.h"
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#include "include/file.h"
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#include "include/ipc.h"
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#include "include/match.h"
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#include "include/path.h"
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#include "include/policy.h"
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#include "include/policy_unpack.h"
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#include "include/resource.h"
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#include "include/sid.h"
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/* root profile namespace */
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struct aa_namespace *root_ns;
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const char *profile_mode_names[] = {
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"enforce",
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"complain",
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"kill",
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};
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/**
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* hname_tail - find the last component of an hname
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* @name: hname to find the base profile name component of (NOT NULL)
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*
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* Returns: the tail (base profile name) name component of an hname
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*/
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static const char *hname_tail(const char *hname)
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{
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char *split;
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hname = strim((char *)hname);
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for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
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hname = split + 2;
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return hname;
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}
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/**
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* policy_init - initialize a policy structure
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* @policy: policy to initialize (NOT NULL)
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* @prefix: prefix name if any is required. (MAYBE NULL)
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* @name: name of the policy, init will make a copy of it (NOT NULL)
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*
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* Note: this fn creates a copy of strings passed in
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*
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* Returns: true if policy init successful
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*/
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static bool policy_init(struct aa_policy *policy, const char *prefix,
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const char *name)
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{
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/* freed by policy_free */
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if (prefix) {
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policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
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GFP_KERNEL);
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if (policy->hname)
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sprintf(policy->hname, "%s//%s", prefix, name);
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} else
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policy->hname = kstrdup(name, GFP_KERNEL);
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if (!policy->hname)
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return 0;
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/* base.name is a substring of fqname */
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policy->name = (char *)hname_tail(policy->hname);
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INIT_LIST_HEAD(&policy->list);
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INIT_LIST_HEAD(&policy->profiles);
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kref_init(&policy->count);
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return 1;
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}
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/**
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* policy_destroy - free the elements referenced by @policy
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* @policy: policy that is to have its elements freed (NOT NULL)
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*/
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static void policy_destroy(struct aa_policy *policy)
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{
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/* still contains profiles -- invalid */
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if (!list_empty(&policy->profiles)) {
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AA_ERROR("%s: internal error, "
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"policy '%s' still contains profiles\n",
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__func__, policy->name);
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BUG();
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}
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if (!list_empty(&policy->list)) {
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AA_ERROR("%s: internal error, policy '%s' still on list\n",
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__func__, policy->name);
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BUG();
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}
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/* don't free name as its a subset of hname */
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kzfree(policy->hname);
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}
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/**
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* __policy_find - find a policy by @name on a policy list
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* @head: list to search (NOT NULL)
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* @name: name to search for (NOT NULL)
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*
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* Requires: correct locks for the @head list be held
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*
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* Returns: unrefcounted policy that match @name or NULL if not found
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*/
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static struct aa_policy *__policy_find(struct list_head *head, const char *name)
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{
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struct aa_policy *policy;
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list_for_each_entry(policy, head, list) {
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if (!strcmp(policy->name, name))
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return policy;
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}
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return NULL;
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}
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/**
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* __policy_strn_find - find a policy that's name matches @len chars of @str
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* @head: list to search (NOT NULL)
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* @str: string to search for (NOT NULL)
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* @len: length of match required
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*
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* Requires: correct locks for the @head list be held
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*
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* Returns: unrefcounted policy that match @str or NULL if not found
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*
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* if @len == strlen(@strlen) then this is equiv to __policy_find
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* other wise it allows searching for policy by a partial match of name
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*/
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static struct aa_policy *__policy_strn_find(struct list_head *head,
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const char *str, int len)
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{
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struct aa_policy *policy;
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list_for_each_entry(policy, head, list) {
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if (aa_strneq(policy->name, str, len))
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return policy;
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}
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return NULL;
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}
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/*
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* Routines for AppArmor namespaces
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*/
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static const char *hidden_ns_name = "---";
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/**
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* aa_ns_visible - test if @view is visible from @curr
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* @curr: namespace to treat as the parent (NOT NULL)
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* @view: namespace to test if visible from @curr (NOT NULL)
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*
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* Returns: true if @view is visible from @curr else false
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*/
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bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
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{
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if (curr == view)
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return true;
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for ( ; view; view = view->parent) {
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if (view->parent == curr)
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return true;
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}
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return false;
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}
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/**
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* aa_na_name - Find the ns name to display for @view from @curr
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* @curr - current namespace (NOT NULL)
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* @view - namespace attempting to view (NOT NULL)
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*
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* Returns: name of @view visible from @curr
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*/
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const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
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{
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/* if view == curr then the namespace name isn't displayed */
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if (curr == view)
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return "";
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if (aa_ns_visible(curr, view)) {
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/* at this point if a ns is visible it is in a view ns
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* thus the curr ns.hname is a prefix of its name.
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* Only output the virtualized portion of the name
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* Add + 2 to skip over // separating curr hname prefix
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* from the visible tail of the views hname
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*/
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return view->base.hname + strlen(curr->base.hname) + 2;
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} else
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return hidden_ns_name;
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}
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/**
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* alloc_namespace - allocate, initialize and return a new namespace
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* @prefix: parent namespace name (MAYBE NULL)
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* @name: a preallocated name (NOT NULL)
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*
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* Returns: refcounted namespace or NULL on failure.
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*/
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static struct aa_namespace *alloc_namespace(const char *prefix,
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const char *name)
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{
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struct aa_namespace *ns;
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ns = kzalloc(sizeof(*ns), GFP_KERNEL);
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AA_DEBUG("%s(%p)\n", __func__, ns);
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if (!ns)
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return NULL;
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if (!policy_init(&ns->base, prefix, name))
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goto fail_ns;
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INIT_LIST_HEAD(&ns->sub_ns);
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rwlock_init(&ns->lock);
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/* released by free_namespace */
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ns->unconfined = aa_alloc_profile("unconfined");
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if (!ns->unconfined)
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goto fail_unconfined;
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ns->unconfined->sid = aa_alloc_sid();
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ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
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PFLAG_IMMUTABLE;
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/*
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* released by free_namespace, however __remove_namespace breaks
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* the cyclic references (ns->unconfined, and unconfined->ns) and
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* replaces with refs to parent namespace unconfined
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*/
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ns->unconfined->ns = aa_get_namespace(ns);
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return ns;
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fail_unconfined:
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kzfree(ns->base.hname);
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fail_ns:
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kzfree(ns);
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return NULL;
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}
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/**
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* free_namespace - free a profile namespace
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* @ns: the namespace to free (MAYBE NULL)
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*
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* Requires: All references to the namespace must have been put, if the
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* namespace was referenced by a profile confining a task,
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*/
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static void free_namespace(struct aa_namespace *ns)
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{
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if (!ns)
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return;
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policy_destroy(&ns->base);
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aa_put_namespace(ns->parent);
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if (ns->unconfined && ns->unconfined->ns == ns)
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ns->unconfined->ns = NULL;
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aa_put_profile(ns->unconfined);
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kzfree(ns);
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}
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/**
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* aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
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* @kr: kref callback for freeing of a namespace (NOT NULL)
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*/
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void aa_free_namespace_kref(struct kref *kref)
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{
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free_namespace(container_of(kref, struct aa_namespace, base.count));
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}
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/**
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* __aa_find_namespace - find a namespace on a list by @name
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* @head: list to search for namespace on (NOT NULL)
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* @name: name of namespace to look for (NOT NULL)
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*
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* Returns: unrefcounted namespace
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*
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* Requires: ns lock be held
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*/
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static struct aa_namespace *__aa_find_namespace(struct list_head *head,
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const char *name)
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{
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return (struct aa_namespace *)__policy_find(head, name);
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}
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/**
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* aa_find_namespace - look up a profile namespace on the namespace list
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* @root: namespace to search in (NOT NULL)
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* @name: name of namespace to find (NOT NULL)
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*
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* Returns: a refcounted namespace on the list, or NULL if no namespace
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* called @name exists.
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*
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* refcount released by caller
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*/
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struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
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const char *name)
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{
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struct aa_namespace *ns = NULL;
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read_lock(&root->lock);
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ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
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read_unlock(&root->lock);
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return ns;
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}
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/**
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* aa_prepare_namespace - find an existing or create a new namespace of @name
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* @name: the namespace to find or add (MAYBE NULL)
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*
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* Returns: refcounted namespace or NULL if failed to create one
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*/
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static struct aa_namespace *aa_prepare_namespace(const char *name)
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{
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struct aa_namespace *ns, *root;
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root = aa_current_profile()->ns;
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write_lock(&root->lock);
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/* if name isn't specified the profile is loaded to the current ns */
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if (!name) {
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/* released by caller */
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ns = aa_get_namespace(root);
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goto out;
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}
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/* try and find the specified ns and if it doesn't exist create it */
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/* released by caller */
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ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
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if (!ns) {
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/* namespace not found */
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struct aa_namespace *new_ns;
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write_unlock(&root->lock);
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new_ns = alloc_namespace(root->base.hname, name);
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if (!new_ns)
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return NULL;
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write_lock(&root->lock);
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/* test for race when new_ns was allocated */
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ns = __aa_find_namespace(&root->sub_ns, name);
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if (!ns) {
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/* add parent ref */
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new_ns->parent = aa_get_namespace(root);
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list_add(&new_ns->base.list, &root->sub_ns);
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/* add list ref */
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ns = aa_get_namespace(new_ns);
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} else {
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/* raced so free the new one */
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free_namespace(new_ns);
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/* get reference on namespace */
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aa_get_namespace(ns);
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}
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}
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out:
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write_unlock(&root->lock);
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/* return ref */
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return ns;
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}
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|
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/**
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* __list_add_profile - add a profile to a list
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* @list: list to add it to (NOT NULL)
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* @profile: the profile to add (NOT NULL)
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*
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* refcount @profile, should be put by __list_remove_profile
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*
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* Requires: namespace lock be held, or list not be shared
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*/
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static void __list_add_profile(struct list_head *list,
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struct aa_profile *profile)
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{
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list_add(&profile->base.list, list);
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/* get list reference */
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aa_get_profile(profile);
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}
|
|
|
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/**
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* __list_remove_profile - remove a profile from the list it is on
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* @profile: the profile to remove (NOT NULL)
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*
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* remove a profile from the list, warning generally removal should
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* be done with __replace_profile as most profile removals are
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* replacements to the unconfined profile.
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*
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* put @profile list refcount
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*
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* Requires: namespace lock be held, or list not have been live
|
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*/
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static void __list_remove_profile(struct aa_profile *profile)
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{
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list_del_init(&profile->base.list);
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if (!(profile->flags & PFLAG_NO_LIST_REF))
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/* release list reference */
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aa_put_profile(profile);
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}
|
|
|
|
/**
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* __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
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|
*
|
|
* 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;
|
|
|
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if (old->parent)
|
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policy = &old->parent->base;
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else
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policy = &old->ns->base;
|
|
|
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/* released when @new is freed */
|
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new->parent = aa_get_profile(old->parent);
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new->ns = aa_get_namespace(old->ns);
|
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new->sid = old->sid;
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__list_add_profile(&policy->profiles, new);
|
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/* inherit children */
|
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list_for_each_entry_safe(child, tmp, &old->base.profiles, base.list) {
|
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aa_put_profile(child->parent);
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child->parent = aa_get_profile(new);
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/* list refcount transferred to @new*/
|
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list_move(&child->base.list, &new->base.profiles);
|
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}
|
|
|
|
/* released by free_profile */
|
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old->replacedby = aa_get_profile(new);
|
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__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
|
|
* @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-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_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 @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;
|
|
|
|
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;
|
|
COMMON_AUDIT_DATA_INIT(&sa, NONE);
|
|
sa.aad.op = op;
|
|
sa.aad.name = name;
|
|
sa.aad.info = info;
|
|
sa.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;
|
|
}
|