blob: 5efd2cf401b4217c96bc3452a0f0a7e3fd963004 [file] [log] [blame]
/*
* AppArmor security module
*
* This file contains AppArmor label definitions
*
* Copyright 2013 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.
*/
#include <linux/audit.h>
#include <linux/seq_file.h>
#include "include/apparmor.h"
#include "include/label.h"
#include "include/policy.h"
#include "include/sid.h"
/*
* the aa_label represents the set of profiles confining an object
*
* Labels maintain a reference count to the set of pointers they reference
* Labels are ref counted by
* tasks and object via the security field/security context off the field
* code - will take a ref count on a label if it needs the label
* beyond what is possible with an rcu_read_lock.
* profiles - each profile is a label
* sids - a pinned sid will keep a refcount of the label it is
* referencing
* objects - inode, files, sockets, ...
*
* Labels are not ref counted by the label set, so they maybe removed and
* freed when no longer in use.
*
*/
static void free_replacedby(struct aa_replacedby *r)
{
if (r) {
/* r->label will not updated any more as r is dead */
aa_put_label(rcu_dereference_protected(r->label, true));
kzfree(r);
}
}
void aa_free_replacedby_kref(struct kref *kref)
{
struct aa_replacedby *r = container_of(kref, struct aa_replacedby,
count);
free_replacedby(r);
}
struct aa_replacedby *aa_alloc_replacedby(struct aa_label *l)
{
struct aa_replacedby *r;
r = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL);
if (r) {
kref_init(&r->count);
rcu_assign_pointer(r->label, aa_get_label(l));
}
return r;
}
/* requires profile list write lock held */
void __aa_update_replacedby(struct aa_label *orig, struct aa_label *new)
{
struct aa_label *tmp;
AA_BUG(!orig);
AA_BUG(!new);
AA_BUG(!mutex_is_locked(&labels_ns(orig)->lock));
tmp = rcu_dereference_protected(orig->replacedby->label,
&labels_ns(orig)->lock);
rcu_assign_pointer(orig->replacedby->label, aa_get_label(new));
orig->flags |= FLAG_INVALID;
aa_put_label(tmp);
}
/* helper fn for label_for_each_confined */
int aa_label_next_confined(struct aa_label *l, int i)
{
AA_BUG(!l);
AA_BUG(i < 0);
for (; i < l->size; i++) {
if (!profile_unconfined(l->ent[i]))
return i;
}
return i;
}
static int label_profile_pos(struct aa_label *l, struct aa_profile *profile)
{
struct aa_profile *p;
struct label_it i;
AA_BUG(!profile);
AA_BUG(!l);
label_for_each(i, l, p) {
if (p == profile)
return i.i;
}
return -1;
}
static bool profile_in_label(struct aa_profile *profile, struct aa_label *l)
{
return label_profile_pos(l, profile) != -1;
}
static bool label_profiles_unconfined(struct aa_label *label)
{
struct aa_profile *profile;
struct label_it i;
AA_BUG(!label);
label_for_each(i, label, profile) {
if (!profile_unconfined(profile))
return false;
}
return true;
}
static int profile_cmp(struct aa_profile *a, struct aa_profile *b);
/**
* aa_label_next_not_in_set - return the next profile of @sub not in @set
* @I: label iterator
* @set: label to test against
* @sub: label to if is subset of @set
*
* Returns: profile in @sub that is not in @set, with iterator set pos after
* else NULL if @sub is a subset of @set
*/
struct aa_profile * aa_label_next_not_in_set(struct label_it *I,
struct aa_label *set,
struct aa_label *sub)
{
AA_BUG(!set);
AA_BUG(!I);
AA_BUG(I->i < 0);
AA_BUG(I->i > set->size);
AA_BUG(!sub);
AA_BUG(I->j < 0);
AA_BUG(I->j > sub->size);
while (I->j < sub->size && I->i < set->size) {
int res = profile_cmp(sub->ent[I->j], set->ent[I->i]);
if (res == 0) {
(I->j)++;
(I->i)++;
} else if (res > 0)
(I->i)++;
else
return sub->ent[(I->j)++];
}
if (I->j < sub->size)
return sub->ent[(I->j)++];
return NULL;
}
/**
* aa_label_is_subset - test if @sub is a subset of @set
* @set: label to test against
* @sub: label to test if is subset of @set
*
* Returns: true if @sub is subset of @set
* else false
*/
bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub)
{
struct label_it i = { };
AA_BUG(!set);
AA_BUG(!sub);
if (sub == set)
return true;
return aa_label_next_not_in_set(&i, set, sub) == NULL;
}
void aa_label_destroy(struct aa_label *label)
{
AA_BUG(!label);
if (label_invalid(label))
labelsetstats_dec(labels_set(label), invalid);
if (!label_isprofile(label)) {
struct aa_profile *profile;
struct label_it i;
aa_put_str(label->hname);
label_for_each(i, label, profile)
aa_put_profile(profile);
}
aa_free_sid(label->sid);
aa_put_replacedby(label->replacedby);
}
void aa_label_free(struct aa_label *label)
{
if (!label)
return;
aa_label_destroy(label);
labelstats_inc(freed);
kzfree(label);
}
static void label_free_rcu(struct rcu_head *head)
{
struct aa_label *l = container_of(head, struct aa_label, rcu);
if (l->flags & FLAG_NS_COUNT)
aa_free_namespace(labels_ns(l));
else if (label_isprofile(l))
aa_free_profile(labels_profile(l));
else
aa_label_free(l);
}
bool aa_label_remove(struct aa_labelset *ls, struct aa_label *label);
void aa_label_kref(struct kref *kref)
{
struct aa_label *l = container_of(kref, struct aa_label, count);
struct aa_namespace *ns = labels_ns(l);
if (!ns) {
/* never live, no rcu callback needed, just using the fn */
label_free_rcu(&l->rcu);
return;
}
(void) aa_label_remove(&ns->labels, l);
/* TODO: if compound label and not invalid add to reclaim cache */
call_rcu(&l->rcu, label_free_rcu);
}
bool aa_label_init(struct aa_label *label, int size)
{
AA_BUG(!label);
AA_BUG(size < 1);
label->sid = aa_alloc_sid();
if (label->sid == AA_SID_INVALID)
return false;
label->size = size; /* doesn't include null */
label->ent[size] = NULL; /* null terminate */
kref_init(&label->count);
RB_CLEAR_NODE(&label->node);
return true;
}
/**
* aa_label_alloc - allocate a label with a profile vector of @size length
* @size: size of profile vector in the label
* @gfp: memory allocation type
*
* Returns: new label
* else NULL if failed
*/
struct aa_label *aa_label_alloc(int size, gfp_t gfp)
{
struct aa_label *label;
AA_BUG(size < 1);
/* vector: size - 2 (size of array in label struct) + 1 for null */
label = kzalloc(sizeof(*label) + sizeof(struct aa_label *) * (size - 1),
gfp);
AA_DEBUG("%s (%p)\n", __func__, label);
if (!label)
goto fail;
if (!aa_label_init(label, size))
goto fail;
labelstats_inc(allocated);
return label;
fail:
kfree(label);
labelstats_inc(failed);
return NULL;
}
static bool __aa_label_remove(struct aa_labelset *ls, struct aa_label *label)
{
AA_BUG(!ls);
AA_BUG(!label);
AA_BUG(!write_is_locked(&ls->lock));
AA_BUG(labels_set(label) != ls);
if (label_invalid(label))
labelstats_dec(invalid_intree);
else
__label_invalidate(label);
if (label->flags & FLAG_IN_TREE) {
labelsetstats_dec(ls, intree);
rb_erase(&label->node, &ls->root);
label->flags &= ~FLAG_IN_TREE;
return true;
}
return false;
}
/**
* aa_label_remove - remove a label from the labelset
* @ls: set to remove the label from
* @l: label to remove
*
* Returns: true if @l was removed from the tree
* else @l was not in tree so it could not be removed
*/
bool aa_label_remove(struct aa_labelset *ls, struct aa_label *l)
{
unsigned long flags;
bool res;
write_lock_irqsave(&ls->lock, flags);
res = __aa_label_remove(ls, l);
write_unlock_irqrestore(&ls->lock, flags);
return res;
}
/* don't use when using ptr comparisons because nodes should never be
* the same
*/
static bool __aa_label_replace(struct aa_labelset *ls, struct aa_label *old,
struct aa_label *new)
{
AA_BUG(!ls);
AA_BUG(!old);
AA_BUG(!new);
AA_BUG(!write_is_locked(&ls->lock));
AA_BUG(labels_set(old) != ls);
AA_BUG(new->flags & FLAG_IN_TREE);
if (label_invalid(old))
labelstats_dec(invalid_intree);
else
__label_invalidate(old);
if (old->flags & FLAG_IN_TREE) {
rb_replace_node(&old->node, &new->node, &ls->root);
old->flags &= ~FLAG_IN_TREE;
new->flags |= FLAG_IN_TREE;
return true;
}
return false;
}
static struct aa_label *__aa_label_insert(struct aa_labelset *ls,
struct aa_label *l);
static struct aa_label *__aa_label_remove_and_insert(struct aa_labelset *ls,
struct aa_label *remove,
struct aa_label *insert)
{
AA_BUG(!ls);
AA_BUG(!remove);
AA_BUG(!insert);
AA_BUG(!write_is_locked(&ls->lock));
AA_BUG(labels_set(remove) != ls);
AA_BUG(insert->flags & FLAG_IN_TREE);
__aa_label_remove(ls, remove);
return __aa_label_insert(ls, insert);
}
struct aa_label *aa_label_remove_and_insert(struct aa_labelset *ls,
struct aa_label *remove,
struct aa_label *insert)
{
unsigned long flags;
struct aa_label *l;
write_lock_irqsave(&ls->lock, flags);
l = aa_get_label(__aa_label_remove_and_insert(ls, remove, insert));
write_unlock_irqrestore(&ls->lock, flags);
return l;
}
/**
* aa_label_replace - replace a label @old with a new version @new
* @ls: labelset being manipulated
* @old: label to replace
* @new: label replacing @old
*
* Returns: true if @old was in tree and replaced
* else @old was not in tree, and @new was not inserted
*/
bool aa_label_replace(struct aa_labelset *ls, struct aa_label *old,
struct aa_label *new)
{
struct aa_label *l;
unsigned long flags;
bool res;
write_lock_irqsave(&ls->lock, flags);
if (!(old->flags & FLAG_IN_TREE))
l = __aa_label_insert(ls, new);
else
l = __aa_label_remove_and_insert(ls, old, new);
res = (l == new);
write_unlock_irqrestore(&ls->lock, flags);
return res;
}
static int ns_cmp(struct aa_namespace *a, struct aa_namespace *b)
{
int res;
AA_BUG(!a);
AA_BUG(!b);
AA_BUG(!a->base.name);
AA_BUG(!b->base.name);
if (a == b)
return 0;
res = a->level - b->level;
if (res)
return res;
return strcmp(a->base.name, b->base.name);
}
/**
* profile_cmp - profile comparision for set ordering
* @a: profile to compare (NOT NULL)
* @b: profile to compare (NOT NULL)
*
* Returns: <0 if a < b
* ==0 if a == b
* >0 if a > b
*/
static int profile_cmp(struct aa_profile *a, struct aa_profile *b)
{
int res;
AA_BUG(!a);
AA_BUG(!b);
AA_BUG(!a->ns);
AA_BUG(!b->ns);
AA_BUG(!a->base.hname);
AA_BUG(!b->base.hname);
if (a == b || a->base.hname == b->base.hname)
return 0;
res = ns_cmp(a->ns, b->ns);
if (res)
return res;
return strcmp(a->base.hname, b->base.hname);
}
/**
* label_vec_cmp - label comparision for set ordering
* @a: label to compare (NOT NULL)
* @vec: vector of profiles to compare (NOT NULL)
* @n: length of @vec
*
* Returns: <0 if a < vec
* ==0 if a == vec
* >0 if a > vec
*/
static int label_vec_cmp(struct aa_label *a, struct aa_profile **vec, int n)
{
int i;
AA_BUG(!a);
AA_BUG(!vec);
AA_BUG(!*vec);
AA_BUG(n <= 0);
for (i = 0; i < a->size && i < n; i++) {
int res = profile_cmp(a->ent[i], vec[i]);
if (res != 0)
return res;
}
return a->size - n;
}
/**
* label_cmp - label comparision for set ordering
* @a: label to compare (NOT NULL)
* @b: label to compare (NOT NULL)
*
* Returns: <0 if a < b
* ==0 if a == b
* >0 if a > b
*/
static int label_cmp(struct aa_label *a, struct aa_label *b)
{
AA_BUG(!b);
if (a == b)
return 0;
return label_vec_cmp(a, b->ent, b->size);
}
/**
* __aa_label_vec_find - find label that matches @vec in label set
* @ls: set of labels to search (NOT NULL)
* @vec: vec of profiles to find matching label for (NOT NULL)
* @n: length of @vec
*
* Requires: @ls lock held
* caller to hold a valid ref on l
*
* Returns: unref counted @label if matching label is in tree
* else NULL if @vec equiv is not in tree
*/
static struct aa_label *__aa_label_vec_find(struct aa_labelset *ls,
struct aa_profile **vec, int n)
{
struct rb_node *node;
AA_BUG(!ls);
AA_BUG(!vec);
AA_BUG(!*vec);
AA_BUG(n <= 0);
node = ls->root.rb_node;
while (node) {
struct aa_label *this = rb_entry(node, struct aa_label, node);
int result = label_vec_cmp(this, vec, n);
if (result > 0)
node = node->rb_left;
else if (result < 0)
node = node->rb_right;
else
return this;
}
return NULL;
}
/**
* __aa_label_find - find label @l in label set
* @ls: set of labels to search (NOT NULL)
* @l: label to find (NOT NULL)
*
* Requires: @ls lock held
* caller to hold a valid ref on l
*
* Returns: unref counted @l if @l is in tree
* unref counted label that is equiv to @l in tree
* else NULL if @l or equiv is not in tree
*/
static struct aa_label *__aa_label_find(struct aa_labelset *ls,
struct aa_label *l)
{
AA_BUG(!l);
return __aa_label_vec_find(ls, l->ent, l->size);
}
/**
* aa_label_vec_find - find label @l in label set
* @ls: set of labels to search (NOT NULL)
* @vec: array of profiles to find equiv label for (NOT NULL)
* @n: length of @vec
*
* Returns: refcounted label if @vec equiv is in tree
* else NULL if @vec equiv is not in tree
*/
struct aa_label *aa_label_vec_find(struct aa_labelset *ls,
struct aa_profile **vec,
int n)
{
struct aa_label *label;
unsigned long flags;
AA_BUG(!ls);
AA_BUG(!vec);
AA_BUG(!*vec);
AA_BUG(n <= 0);
read_lock_irqsave(&ls->lock, flags);
label = aa_get_label(__aa_label_vec_find(ls, vec, n));
labelstats_inc(sread);
read_unlock_irqrestore(&ls->lock, flags);
return label;
}
/**
* aa_label_find - find label @l in label set
* @ls: set of labels to search (NOT NULL)
* @l: label to find (NOT NULL)
*
* Requires: caller to hold a valid ref on l
*
* Returns: refcounted @l if @l is in tree
* refcounted label that is equiv to @l in tree
* else NULL if @l or equiv is not in tree
*/
struct aa_label *aa_label_find(struct aa_labelset *ls, struct aa_label *l)
{
AA_BUG(!l);
return aa_label_vec_find(ls, l->ent, l->size);
}
/**
* __aa_label_insert - attempt to insert @l into a label set
* @ls: set of labels to insert @l into (NOT NULL)
* @l: new label to insert (NOT NULL)
*
* Requires: @ls->lock
* caller to hold a valid ref on l
*
* Returns: @l if successful in inserting @l
* else ref counted equivalent label that is already in the set.
*/
static struct aa_label *__aa_label_insert(struct aa_labelset *ls,
struct aa_label *l)
{
struct rb_node **new, *parent = NULL;
AA_BUG(!ls);
AA_BUG(!l);
AA_BUG(!write_is_locked(&ls->lock));
AA_BUG(l->flags & FLAG_IN_TREE);
/* Figure out where to put new node */
new = &ls->root.rb_node;
while (*new) {
struct aa_label *this = rb_entry(*new, struct aa_label, node);
int result = label_cmp(l, this);
parent = *new;
if (result == 0) {
labelsetstats_inc(ls, existing);
return this;
} else if (result < 0)
new = &((*new)->rb_left);
else /* (result > 0) */
new = &((*new)->rb_right);
}
/* Add new node and rebalance tree. */
rb_link_node(&l->node, parent, new);
rb_insert_color(&l->node, &ls->root);
l->flags |= FLAG_IN_TREE;
labelsetstats_inc(ls, insert);
labelsetstats_inc(ls, intree);
return l;
}
/**
* aa_label_insert - insert label @l into @ls or return existing label
* @ls - labelset to insert @l into
* @l - label to insert
*
* Requires: caller to hold a valid ref on l
*
* Returns: ref counted @l if successful in inserting @l
* else ref counted equivalent label that is already in the set
*/
struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l)
{
struct aa_label *label;
unsigned long flags;
AA_BUG(!ls);
AA_BUG(!l);
/* check if label exists before taking lock */
if (!label_invalid(l)) {
read_lock_irqsave(&ls->lock, flags);
label = aa_get_label(__aa_label_find(ls, l));
read_unlock_irqrestore(&ls->lock, flags);
labelstats_inc(fread);
if (label)
return label;
}
write_lock_irqsave(&ls->lock, flags);
label = aa_get_label(__aa_label_insert(ls, l));
write_unlock_irqrestore(&ls->lock, flags);
return label;
}
struct aa_label *aa_label_vec_find_or_create(struct aa_labelset *ls,
struct aa_profile **vec, int len)
{
struct aa_label *label = aa_label_vec_find(ls, vec, len);
if (label)
return label;
return aa_label_vec_merge(vec, len, GFP_KERNEL);
}
/**
* aa_label_next_in_merge - find the next profile when merging @a and @b
* @I: label iterator
* @a: label to merge
* @b: label to merge
*
* Returns: next profile
* else null if no more profiles
*/
struct aa_profile *aa_label_next_in_merge(struct label_it *I,
struct aa_label *a,
struct aa_label *b)
{
AA_BUG(!a);
AA_BUG(!b);
AA_BUG(!I);
AA_BUG(I->i < 0);
AA_BUG(I->i > a->size);
AA_BUG(I->j < 0);
AA_BUG(I->j > b->size);
if (I->i < a->size) {
if (I->j < b->size) {
int res = profile_cmp(a->ent[I->i], b->ent[I->j]);
if (res > 0)
return b->ent[(I->j)++];
if (res == 0)
(I->j)++;
}
return a->ent[(I->i)++];
}
if (I->j < b->size)
return b->ent[(I->j)++];
return NULL;
}
/**
* label_merge_cmp - cmp of @a merging with @b against @z for set ordering
* @a: label to merge then compare (NOT NULL)
* @b: label to merge then compare (NOT NULL)
* @z: label to compare merge against (NOT NULL)
*
* Assumes: using the most recent versions of @a, @b, and @z
*
* Returns: <0 if a < b
* ==0 if a == b
* >0 if a > b
*/
static int label_merge_cmp(struct aa_label *a, struct aa_label *b,
struct aa_label *z)
{
struct aa_profile *p = NULL;
struct label_it i = { };
int k;
AA_BUG(!a);
AA_BUG(!b);
AA_BUG(!z);
for (k = 0;
k < z->size && (p = aa_label_next_in_merge(&i, a, b));
k++) {
int res = profile_cmp(p, z->ent[k]);
if (res != 0)
return res;
}
if (p)
return 1;
else if (k < z->size)
return -1;
return 0;
}
/**
* label_merge_len - find the length of the merge of @a and @b
* @a: label to merge (NOT NULL)
* @b: label to merge (NOT NULL)
*
* Assumes: using newest versions of labels @a and @b
*
* Returns: length of a label vector for merge of @a and @b
*/
static int label_merge_len(struct aa_label *a, struct aa_label *b)
{
int len = a->size + b->size;
int i, j;
AA_BUG(!a);
AA_BUG(!b);
/* find entries in common and remove from count */
for (i = j = 0; i < a->size && j < b->size; ) {
int res = profile_cmp(a->ent[i], b->ent[j]);
if (res == 0) {
len--;
i++;
j++;
} else if (res < 0)
i++;
else
j++;
}
return len;
}
/**
* aa_sort_and_merge_profiles - canonical sort and merge a list of profiles
* @n: number of refcounted profiles in the list (@n > 0)
* @ps: list of profiles to sort and merge
*
* Returns: the number of duplicates eliminated == references put
*/
static int aa_sort_and_merge_profiles(int n, struct aa_profile **ps)
{
int i, dups = 0;
AA_BUG(n < 1);
AA_BUG(!ps);
/* label lists are usually small so just use insertion sort */
for (i = 1; i < n; i++) {
struct aa_profile *tmp = ps[i];
int pos, j;
for (pos = i - 1 - dups; pos >= 0; pos--) {
int res = profile_cmp(ps[pos], tmp);
if (res == 0) {
aa_put_profile(tmp);
dups++;
goto continue_outer;
} else if (res < 0)
break;
}
pos++;
for (j = i - dups; j > pos; j--)
ps[j] = ps[j - 1];
ps[pos] = tmp;
continue_outer:
; /* sigh empty statement required after the label */
}
return dups;
}
/**
* __label_merge - create a new label by merging @a and @b
* @l: preallocated label to merge into (NOT NULL)
* @a: label to merge with @b (NOT NULL)
* @b: label to merge with @a (NOT NULL)
*
* Returns: ref counted label either l if merge is unique
* a if b is a subset of a
* b if a is a subset of b
*
* NOTE: will not use l if the merge results in l == a or b
*
* Must be used within labelset write lock to avoid racing with
* label invalidation.
*/
static struct aa_label *__label_merge(struct aa_label *l, struct aa_label *a,
struct aa_label *b)
{
struct aa_profile *next;
struct label_it i;
int k = 0, invcount = 0;
AA_BUG(!a);
AA_BUG(a->size < 0);
AA_BUG(!b);
AA_BUG(b->size < 0);
AA_BUG(!l);
AA_BUG(l->size < a->size + b->size);
if (a == b)
return aa_get_label(a);
label_for_each_in_merge(i, a, b, next) {
if (PROFILE_INVALID(next)) {
l->ent[k] = aa_get_newest_profile(next);
if (next->label.replacedby !=
l->ent[k]->label.replacedby)
invcount++;
k++;
} else
l->ent[k++] = aa_get_profile(next);
}
/* set to actual size which is <= allocated len */
l->size = k;
l->ent[k] = NULL;
if (invcount) {
l->size -= aa_sort_and_merge_profiles(l->size, &l->ent[0]);
if (label_profiles_unconfined(l))
l->flags |= FLAG_UNCONFINED;
} else {
/* merge is same as at least one of the labels */
if (k == a->size)
return aa_get_label(a);
else if (k == b->size)
return aa_get_label(b);
l->flags |= a->flags & b->flags & FLAG_UNCONFINED;
}
return aa_get_label(l);
}
/**
* labelset_of_merge - find into which labelset a merged label should be inserted
* @a: label to merge and insert
* @b: label to merge and insert
*
* Returns: labelset that the merged label should be inserted into
*/
static struct aa_labelset *labelset_of_merge(struct aa_label *a, struct aa_label *b)
{
struct aa_namespace *nsa = labels_ns(a);
struct aa_namespace *nsb = labels_ns(b);
if (ns_cmp(nsa, nsb) <= 0)
return &nsa->labels;
return &nsb->labels;
}
/**
* __aa_label_find_merge - find label that is equiv to merge of @a and @b
* @ls: set of labels to search (NOT NULL)
* @a: label to merge with @b (NOT NULL)
* @b: label to merge with @a (NOT NULL)
*
* Requires: read_lock held
*
* Returns: unref counted label that is equiv to merge of @a and @b
* else NULL if merge of @a and @b is not in set
*/
static struct aa_label *__aa_label_find_merge(struct aa_labelset *ls,
struct aa_label *a,
struct aa_label *b)
{
struct rb_node *node;
AA_BUG(!ls);
AA_BUG(!a);
AA_BUG(!b);
if (a == b)
return __aa_label_find(ls, a);
node = ls->root.rb_node;
while (node) {
struct aa_label *this = container_of(node, struct aa_label,
node);
int result = label_merge_cmp(a, b, this);
if (result < 0)
node = node->rb_left;
else if (result > 0)
node = node->rb_right;
else
return this;
}
return NULL;
}
/**
* __aa_label_find_merge - find label that is equiv to merge of @a and @b
* @a: label to merge with @b (NOT NULL)
* @b: label to merge with @a (NOT NULL)
*
* Requires: labels be fully constructed with a valid ns
*
* Returns: ref counted label that is equiv to merge of @a and @b
* else NULL if merge of @a and @b is not in set
*/
struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b)
{
struct aa_labelset *ls;
struct aa_label *label, *ar = NULL, *br = NULL;
unsigned long flags;
AA_BUG(!a);
AA_BUG(!b);
ls = labelset_of_merge(a, b);
read_lock_irqsave(&ls->lock, flags);
if (label_invalid(a))
a = ar = aa_get_newest_label(a);
if (label_invalid(b))
b = br = aa_get_newest_label(b);
label = aa_get_label(__aa_label_find_merge(ls, a, b));
read_unlock_irqrestore(&ls->lock, flags);
aa_put_label(ar);
aa_put_label(br);
labelsetstats_inc(ls, msread);
return label;
}
/**
* aa_label_merge - attempt to insert new merged label of @a and @b
* @ls: set of labels to insert label into (NOT NULL)
* @a: label to merge with @b (NOT NULL)
* @b: label to merge with @a (NOT NULL)
* @gfp: memory allocation type
*
* Requires: caller to hold valid refs on @a and @b
* labels be fully constructed with a valid ns
*
* Returns: ref counted new label if successful in inserting merge of a & b
* else ref counted equivalent label that is already in the set.
* else NULL if could not create label (-ENOMEM)
*/
struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
gfp_t gfp)
{
struct aa_label *label = NULL;
struct aa_labelset *ls;
unsigned long flags;
AA_BUG(!a);
AA_BUG(!b);
if (a == b)
return aa_get_newest_label(a);
ls = labelset_of_merge(a, b);
/* TODO: enable when read side is lockless
* check if label exists before taking locks
if (!label_invalid(a) && !label_invalid(b))
label = aa_label_find_merge(a, b);
*/
if (!label) {
struct aa_label *new, *l;
a = aa_get_newest_label(a);
b = aa_get_newest_label(b);
/* could use label_merge_len(a, b), but requires double
* comparison for small savings
*/
new = aa_label_alloc(a->size + b->size, gfp);
if (!new)
return NULL;
write_lock_irqsave(&ls->lock, flags);
l = __label_merge(new, a, b);
if (l != new) {
/* new may not be fully setup so no put_label */
aa_label_free(new);
new = NULL;
}
if (!(l->flags & FLAG_IN_TREE))
label = aa_get_label(__aa_label_insert(ls, l));
write_unlock_irqrestore(&ls->lock, flags);
aa_put_label(new);
aa_put_label(l);
aa_put_label(a);
aa_put_label(b);
}
return label;
}
/* requires sort and merge done first */
struct aa_label *aa_label_vec_merge(struct aa_profile **vec, int len,
gfp_t gfp)
{
struct aa_label *label = NULL;
struct aa_labelset *ls;
unsigned long flags;
struct aa_label *new;
int i;
AA_BUG(!vec);
if (len == 1)
return aa_get_label(&vec[0]->label);
ls = labels_set(&vec[len - 1]->label);
/* TODO: enable when read side is lockless
* check if label exists before taking locks
*/
new = aa_label_alloc(len, gfp);
if (!new)
return NULL;
write_lock_irqsave(&ls->lock, flags);
for (i = 0; i < len; i++) {
new->ent[i] = aa_get_profile(vec[i]);
label = __aa_label_insert(ls, new);
if (label != new) {
aa_get_label(label);
/* not fully constructed don't put */
aa_label_free(new);
}
}
write_unlock_irqrestore(&ls->lock, flags);
return label;
}
/**
* aa_update_label_name - update a label to have a stored name
* @ns: ns being viewed from (NOT NULL)
* @label: label to update (NOT NULL)
* @gfp: type of memory allocation
*
* Requires: labels_set(label) not locked in caller
*
* note: only updates the label name if it does not have a name already
* and if it is in the labelset
*/
bool aa_update_label_name(struct aa_namespace *ns, struct aa_label *label,
gfp_t gfp)
{
struct aa_labelset *ls;
unsigned long flags;
char __counted *name;
bool res = false;
AA_BUG(!ns);
AA_BUG(!label);
if (label->hname || labels_ns(label) != ns)
return res;
if (aa_label_acntsprint(&name, ns, label, false, gfp) == -1)
return res;
ls = labels_set(label);
write_lock_irqsave(&ls->lock, flags);
if (!label->hname && label->flags & FLAG_IN_TREE) {
label->hname = name;
res = true;
} else
aa_put_str(name);
write_unlock_irqrestore(&ls->lock, flags);
return res;
}
/* cached label name is present and visible
* @label->hname only exists if label is namespace hierachical */
static inline bool label_name_visible(struct aa_namespace *ns,
struct aa_label *label)
{
if (label->hname && labels_ns(label) == ns)
return true;
return false;
}
/* helper macro for snprint routines */
#define update_for_len(total, len, size, str) \
do { \
AA_BUG(len < 0); \
total += len; \
len = min(len, size); \
size -= len; \
str += len; \
} while (0)
/**
* aa_modename_snprint - print the mode name of a profile or label to a buffer
* @str: buffer to write to (MAY BE NULL if @size == 0)
* @size: size of buffer
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to print the mode of (NOT NULL)
*
* Returns: size of name written or would be written if larger than
* available buffer
*
* Note: will print every mode name visible (mode1)(mode2)(mode3)
* this is likely not what is desired for most interfaces
* use aa_mode_snprint to get the standard mode format
*/
static int aa_modename_snprint(char *str, size_t size, struct aa_namespace *ns,
struct aa_label *label)
{
struct aa_profile *profile;
struct label_it i;
int total = 0;
size_t len;
label_for_each(i, label, profile) {
const char *modestr;
if (!aa_ns_visible(ns, profile->ns))
continue;
/* no mode for 'unconfined' */
if (profile_unconfined(profile) &&
profile == profile->ns->unconfined)
break;
modestr = aa_profile_mode_names[profile->mode];
len = snprintf(str, size, "(%s)", modestr);
update_for_len(total, len, size, str);
}
return total;
}
/**
* aa_modechr_snprint - print the mode chr of a profile or labels to a buffer
* @str: buffer to write to (MAY BE NULL if @size == 0)
* @size: size of buffer
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to print the mode chr of (NOT NULL)
*
* Returns: size of mode string written or would be written if larger than
* available buffer
*
* Note: will print the chr of every visible profile (123)
* this is likely not what is desired for most interfaces
* use aa_mode_snprint to get the standard mode format
*/
static int aa_modechr_snprint(char *str, size_t size, struct aa_namespace *ns,
struct aa_label *label)
{
struct aa_profile *profile;
struct label_it i;
int total = 0;
size_t len;
len = snprintf(str, size, "(");
update_for_len(total, len, size, str);
label_for_each(i, label, profile) {
const char *modestr;
if (!aa_ns_visible(ns, profile->ns))
continue;
modestr = aa_profile_mode_names[profile->mode];
/* just the first char of the modestr */
len = snprintf(str, size, "%c", *modestr);
update_for_len(total, len, size, str);
}
len = snprintf(str, size, ")");
update_for_len(total, len, size, str);
return total;
}
/**
* aa_mode_snprint - print the mode of a profile or label to a buffer
* @str: buffer to write to (MAY BE NULL if @size == 0)
* @size: size of buffer
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to print the mode of (NOT NULL)
* @count: number of label entries to be printed (<= 0 if unknown)
*
* Returns: size of name written or would be written if larger than
* available buffer
*
* Note: dynamically switches between mode name, and mode char format as
* appropriate
* will not print anything if the label is not visible
*/
static int aa_mode_snprint(char *str, size_t size, struct aa_namespace *ns,
struct aa_label *label, int count)
{
struct aa_profile *profile;
struct label_it i;
if (count <= 0) {
count = 0;
label_for_each(i, label, profile) {
if (aa_ns_visible(ns, profile->ns))
count++;
}
}
if (count == 0)
return 0;
if (count == 1)
return aa_modename_snprint(str, size, ns, label);
return aa_modechr_snprint(str, size, ns, label);
}
/**
* aa_snprint_profile - print a profile name to a buffer
* @str: buffer to write to. (MAY BE NULL if @size == 0)
* @size: size of buffer
* @ns: namespace profile is being viewed from (NOT NULL)
* @profile: profile to view (NOT NULL)
* @mode: whether to include the mode string
*
* Returns: size of name written or would be written if larger than
* available buffer
*
* Note: will not print anything if the profile is not visible
*/
int aa_profile_snprint(char *str, size_t size, struct aa_namespace *ns,
struct aa_profile *profile, bool mode)
{
const char *ns_name = aa_ns_name(ns, profile->ns);
AA_BUG(!str && size != 0);
AA_BUG(!ns);
AA_BUG(!profile);
if (!ns_name)
return 0;
if (mode && profile != profile->ns->unconfined) {
const char *modestr = aa_profile_mode_names[profile->mode];
if (strlen(ns_name))
return snprintf(str, size, ":%s://%s (%s)", ns_name,
profile->base.hname, modestr);
return snprintf(str, size, "%s (%s)", profile->base.hname,
modestr);
}
if (strlen(ns_name))
return snprintf(str, size, ":%s://%s", ns_name,
profile->base.hname);
return snprintf(str, size, "%s", profile->base.hname);
}
/**
* aa_label_snprint - print a label name to a string buffer
* @str: buffer to write to. (MAY BE NULL if @size == 0)
* @size: size of buffer
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to view (NOT NULL)
* @mode: whether to include the mode string
*
* Returns: size of name written or would be written if larger than
* available buffer
*
* Note: labels do not have to be strictly hierarchical to the ns as
* objects may be shared across different namespaces and thus
* pickup labeling from each ns. If a particular part of the
* label is not visible it will just be excluded. And if none
* of the label is visible "---" will be used.
*/
int aa_label_snprint(char *str, size_t size, struct aa_namespace *ns,
struct aa_label *label, bool mode)
{
struct aa_profile *profile;
struct label_it i;
int count = 0, total = 0;
size_t len;
AA_BUG(!str && size != 0);
AA_BUG(!ns);
AA_BUG(!label);
label_for_each(i, label, profile) {
if (aa_ns_visible(ns, profile->ns)) {
if (count > 0) {
len = snprintf(str, size, "//&");
update_for_len(total, len, size, str);
}
len = aa_profile_snprint(str, size, ns, profile, false);
update_for_len(total, len, size, str);
count++;
}
}
if (count == 0)
return snprintf(str, size, aa_hidden_ns_name);
/* count == 1 && ... is for backwards compat where the mode
* is not displayed for 'unconfined' in the current ns
*/
if (mode &&
!(count == 1 && labels_ns(label) == ns &&
labels_profile(label) == ns->unconfined)) {
len = snprintf(str, size, " ");
update_for_len(total, len, size, str);
len = aa_mode_snprint(str, size, ns, label, count);
update_for_len(total, len, size, str);
}
return total;
}
#undef update_for_len
/**
* aa_label_asprint - allocate a string buffer and print label into it
* @strp: Returns - the allocated buffer with the label name. (NOT NULL)
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to view (NOT NULL)
* @mode: whether to include the mode string
* @gfp: kernel memory allocation type
*
* Returns: size of name written or would be written if larger than
* available buffer
*/
int aa_label_asprint(char **strp, struct aa_namespace *ns,
struct aa_label *label, bool mode, gfp_t gfp)
{
int size;
AA_BUG(!strp);
AA_BUG(!ns);
AA_BUG(!label);
size = aa_label_snprint(NULL, 0, ns, label, mode);
if (size < 0)
return size;
*strp = kmalloc(size + 1, gfp);
if (!*strp)
return -ENOMEM;
return aa_label_snprint(*strp, size + 1, ns, label, mode);
}
/**
* aa_label_acntsprint - allocate a __counted string buffer and print label
* @strp: buffer to write to. (MAY BE NULL if @size == 0)
* @ns: namespace profile is being viewed from (NOT NULL)
* @label: label to view (NOT NULL)
* @mode: whether to include the mode string
* @gfp: kernel memory allocation type
*
* Returns: size of name written or would be written if larger than
* available buffer
*/
int aa_label_acntsprint(char __counted **strp, struct aa_namespace *ns,
struct aa_label *label, bool mode, gfp_t gfp)
{
int size;
AA_BUG(!strp);
AA_BUG(!ns);
AA_BUG(!label);
size = aa_label_snprint(NULL, 0, ns, label, mode);
if (size < 0)
return size;
*strp = aa_str_alloc(size + 1, gfp);
if (!*strp)
return -ENOMEM;
return aa_label_snprint(*strp, size + 1, ns, label, mode);
}
void aa_label_audit(struct audit_buffer *ab, struct aa_namespace *ns,
struct aa_label *label, bool mode, gfp_t gfp)
{
const char *str;
char *name = NULL;
int len;
AA_BUG(!ab);
AA_BUG(!ns);
AA_BUG(!label);
if (label_name_visible(ns, label)) {
str = (char *) label->hname;
len = strlen(str);
} else {
labelstats_inc(audit_name_alloc);
len = aa_label_asprint(&name, ns, label, mode, gfp);
if (len == -1) {
labelstats_inc(audit_name_fail);
AA_DEBUG("label print error");
return;
}
str = name;
}
if (audit_string_contains_control(str, len))
audit_log_n_hex(ab, str, len);
else
audit_log_n_string(ab, str, len);
kfree(name);
}
void aa_label_seq_print(struct seq_file *f, struct aa_namespace *ns,
struct aa_label *label, bool mode, gfp_t gfp)
{
AA_BUG(!f);
AA_BUG(!ns);
AA_BUG(!label);
if (!label_name_visible(ns, label)) {
char *str;
int len;
labelstats_inc(seq_print_name_alloc);
len = aa_label_asprint(&str, ns, label, mode, gfp);
if (len == -1) {
labelstats_inc(seq_print_name_fail);
AA_DEBUG("label print error");
return;
}
seq_printf(f, "%s", str);
kfree(str);
} else
seq_printf(f, "%s", label->hname);
}
void aa_label_printk(struct aa_namespace *ns, struct aa_label *label, bool mode,
gfp_t gfp)
{
char *str;
int len;
AA_BUG(!label);
if (!ns)
ns = labels_ns(label);
if (!label_name_visible(ns, label)) {
labelstats_inc(printk_name_alloc);
len = aa_label_asprint(&str, ns, label, mode, gfp);
if (len == -1) {
labelstats_inc(printk_name_fail);
AA_DEBUG("label print error");
return;
}
printk("%s", str);
kfree(str);
} else
printk("%s", label->hname);
}
static int label_count_str_entries(const char *str)
{
const char *split;
int count = 1;
AA_BUG(!str);
for (split = strstr(str, "//&"); split; split = strstr(str, "//&")) {
count++;
str = split + 3;
}
return count;
}
/**
* aa_label_parse - parse, validate and convert a text string to a label
* @base: base label to use for lookups (NOT NULL)
* @str: null terminated text string (NOT NULL)
* @gfp: allocation type
* @create: true if should create compound labels if they don't exist
*
* Returns: the matching refcounted label if present
* else ERRPTR
*/
struct aa_label *aa_label_parse(struct aa_label *base, char *str, gfp_t gfp,
bool create)
{
DEFINE_PROFILE_VEC(vec, tmp);
struct aa_label *l;
int i, len, error;
char *split;
AA_BUG(!base);
AA_BUG(!str);
len = label_count_str_entries(str);
error = aa_setup_profile_vec(vec, tmp, len);
if (error)
return ERR_PTR(error);
for (split = strstr(str, "//&"), i = 0; split && i < len; i++) {
vec[i] = aa_fqlookupn_profile(base, str, split - str);
if (!vec[i])
goto fail;
str = split + 3;
split = strstr(str, "//&");
}
vec[i] = aa_fqlookupn_profile(base, str, strlen(str));
if (!vec[i])
goto fail;
if (len == 1)
/* no need to free vec as len < LOCAL_VEC_ENTRIES */
return &vec[0]->label;
i = aa_sort_and_merge_profiles(len, vec);
len -= i;
if (create)
l = aa_label_vec_find_or_create(labels_set(base), vec, len);
else
l = aa_label_vec_find(labels_set(base), vec, len);
if (!l)
l = ERR_PTR(-ENOENT);
out:
/* use adjusted len from after sort_and_merge, not original */
aa_cleanup_profile_vec(vec, tmp, len);
return l;
fail:
l = ERR_PTR(-ENOENT);
goto out;
}
/**
* aa_labelset_destroy - remove all labels from the label set
* @ls: label set to cleanup (NOT NULL)
*
* Labels that are removed from the set may still exist beyond the set
* being destroyed depending on their reference counting
*/
void aa_labelset_destroy(struct aa_labelset *ls)
{
struct rb_node *node;
unsigned long flags;
AA_BUG(!ls);
write_lock_irqsave(&ls->lock, flags);
for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) {
struct aa_label *this = rb_entry(node, struct aa_label, node);
__aa_label_remove(ls, this);
}
write_unlock_irqrestore(&ls->lock, flags);
}
/*
* @ls: labelset to init (NOT NULL)
*/
void aa_labelset_init(struct aa_labelset *ls)
{
AA_BUG(!ls);
rwlock_init(&ls->lock);
ls->root = RB_ROOT;
labelstats_init(&ls);
}
static struct aa_label *labelset_next_invalid(struct aa_labelset *ls)
{
struct aa_label *label;
struct rb_node *node;
unsigned long flags;
AA_BUG(!ls);
read_lock_irqsave(&ls->lock, flags);
__labelset_for_each(ls, node) {
struct aa_profile *p;
struct label_it i;
label = rb_entry(node, struct aa_label, node);
if (label_invalid(label))
goto out;
label_for_each(i, label, p) {
if (PROFILE_INVALID(p))
goto out;
}
}
label = NULL;
out:
aa_get_label(label);
read_unlock_irqrestore(&ls->lock, flags);
return label;
}
/**
* __label_update - insert updated version of @label into labelset
* @label - the label to update/repace
*
* Returns: new label that is up to date
* else NULL on failure
*
* Requires: @ns lock be held
*
* Note: worst case is the stale @label does not get updated and has
* to be updated at a later time.
*/
static struct aa_label *__label_update(struct aa_label *label)
{
struct aa_label *l, *tmp;
struct aa_labelset *ls;
struct aa_profile *p;
struct label_it i;
unsigned long flags;
int invcount = 0;
AA_BUG(!label);
AA_BUG(!mutex_is_locked(&labels_ns(label)->lock));
l = aa_label_alloc(label->size, GFP_KERNEL);
if (!l)
return NULL;
if (!label->replacedby) {
struct aa_replacedby *r = aa_alloc_replacedby(l);
if (!r) {
aa_put_label(l);
return NULL;
}
/* only label update will set replacedby so ns lock is enough */
label->replacedby = r;
}
/* while holding the ns_lock will stop profile replacement, removal,
* and label updates, label merging and removal can be occuring
*/
ls = labels_set(label);
write_lock_irqsave(&ls->lock, flags);
/* circular ref only broken by replace or remove */
l->replacedby = aa_get_replacedby(label->replacedby);
__aa_update_replacedby(label, l);
label_for_each(i, label, p) {
l->ent[i.i] = aa_get_newest_profile(p);
if (&l->ent[i.i]->label.replacedby != &p->label.replacedby)
invcount++;
}
/* updated label invalidated by being removed/renamed from labelset */
if (invcount) {
l->size -= aa_sort_and_merge_profiles(l->size, &l->ent[0]);
if (labels_set(label) == labels_set(l)) {
goto insert;
} else {
aa_label_remove(labels_set(label), label);
goto other_ls_insert;
}
} else {
AA_BUG(labels_ns(label) != labels_ns(l));
goto insert;
}
insert:
tmp = __aa_label_remove_and_insert(labels_set(label), label, l);
if (tmp != l) {
printk("apparmor: remove %p invalid %d: '", label, label_invalid(label)); aa_label_printk(labels_ns(label), label, false, GFP_ATOMIC); printk("', with %p invalid %d: '", l , label_invalid(l)); printk("', but found %p invalid %d: '", tmp, label_invalid(tmp)); aa_label_printk(labels_ns(tmp), tmp, false, GFP_ATOMIC); printk("'\n");
if (label_invalid(tmp)) {
AA_BUG(__aa_label_remove_and_insert(labels_set(l), tmp, l) != l);
} else {
aa_put_label(l);
l = aa_get_label(tmp);
}
}
write_unlock_irqrestore(&ls->lock, flags);
return l;
other_ls_insert:
write_unlock_irqrestore(&ls->lock, flags);
tmp = aa_label_insert(labels_set(l), l);
if (tmp != l) {
aa_put_label(l);
l = tmp;
}
return l;
}
/**
* __labelset_update - invalidate and update labels in @ns
* @ns: namespace to update and invalidate labels in (NOT NULL)
*
* Requires: @ns lock be held
*
* Walk the labelset ensuring that all labels are up to date and valid
* Any label that is outdated is replaced and by an updated version
* invalidated and removed from the tree.
*
* If failures happen due to memory pressures then stale labels will
* be left in place until the next pass.
*/
static void __labelset_update(struct aa_namespace *ns)
{
struct aa_label *label;
AA_BUG(!ns);
AA_BUG(!mutex_is_locked(&ns->lock));
do {
label = labelset_next_invalid(&ns->labels);
if (label) {
struct aa_label *l;
l = __label_update(label);
aa_put_label(l);
aa_put_label(label);
}
} while (label);
}
/**
* __aa_labelset_invalidate_all - invalidate labels in @ns and below
* @ns: ns to start invalidation at (NOT NULL)
*
* Requires: @ns lock be held
*
* Invalidates labels based on @p in @ns and any children namespaces.
*/
void __aa_labelset_update_all(struct aa_namespace *ns)
{
struct aa_namespace *child;
AA_BUG(!ns);
AA_BUG(!mutex_is_locked(&ns->lock));
__labelset_update(ns);
list_for_each_entry(child, &ns->sub_ns, base.list) {
mutex_lock(&child->lock);
__aa_labelset_update_all(child);
mutex_unlock(&child->lock);
}
}