linux/security/apparmor/include/label.h
John Johansen 3ed4aaa94f apparmor: fix nnp subset test for unconfined
The subset test is not taking into account the unconfined exception
which will cause profile transitions in the stacked confinement
case to fail when no_new_privs is applied.

This fixes a regression introduced in the fix for
https://bugs.launchpad.net/bugs/1839037

BugLink: https://bugs.launchpad.net/bugs/1844186
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 05:58:04 -08:00

468 lines
13 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* AppArmor security module
*
* This file contains AppArmor label definitions
*
* Copyright 2017 Canonical Ltd.
*/
#ifndef __AA_LABEL_H
#define __AA_LABEL_H
#include <linux/atomic.h>
#include <linux/audit.h>
#include <linux/rbtree.h>
#include <linux/rcupdate.h>
#include "apparmor.h"
#include "lib.h"
struct aa_ns;
#define LOCAL_VEC_ENTRIES 8
#define DEFINE_VEC(T, V) \
struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \
struct aa_ ## T **(V)
#define vec_setup(T, V, N, GFP) \
({ \
if ((N) <= LOCAL_VEC_ENTRIES) { \
typeof(N) i; \
(V) = (_ ## V ## _localtmp); \
for (i = 0; i < (N); i++) \
(V)[i] = NULL; \
} else \
(V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \
(V) ? 0 : -ENOMEM; \
})
#define vec_cleanup(T, V, N) \
do { \
int i; \
for (i = 0; i < (N); i++) { \
if (!IS_ERR_OR_NULL((V)[i])) \
aa_put_ ## T((V)[i]); \
} \
if ((V) != _ ## V ## _localtmp) \
kfree(V); \
} while (0)
#define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1])
#define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns)
#define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels)
#define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size)
struct aa_profile;
#define VEC_FLAG_TERMINATE 1
int aa_vec_unique(struct aa_profile **vec, int n, int flags);
struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
gfp_t gfp);
#define aa_sort_and_merge_vec(N, V) \
aa_sort_and_merge_profiles((N), (struct aa_profile **)(V))
/* struct aa_labelset - set of labels for a namespace
*
* Labels are reference counted; aa_labelset does not contribute to label
* reference counts. Once a label's last refcount is put it is removed from
* the set.
*/
struct aa_labelset {
rwlock_t lock;
struct rb_root root;
};
#define __labelset_for_each(LS, N) \
for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N))
void aa_labelset_destroy(struct aa_labelset *ls);
void aa_labelset_init(struct aa_labelset *ls);
enum label_flags {
FLAG_HAT = 1, /* profile is a hat */
FLAG_UNCONFINED = 2, /* label unconfined only if all */
FLAG_NULL = 4, /* profile is null learning profile */
FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */
FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */
FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */
FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
FLAG_NS_COUNT = 0x80, /* carries NS ref count */
FLAG_IN_TREE = 0x100, /* label is in tree */
FLAG_PROFILE = 0x200, /* label is a profile */
FLAG_EXPLICIT = 0x400, /* explicit static label */
FLAG_STALE = 0x800, /* replaced/removed */
FLAG_RENAMED = 0x1000, /* label has renaming in it */
FLAG_REVOKED = 0x2000, /* label has revocation in it */
/* These flags must correspond with PATH_flags */
/* TODO: add new path flags */
};
struct aa_label;
struct aa_proxy {
struct kref count;
struct aa_label __rcu *label;
};
struct label_it {
int i, j;
};
/* struct aa_label - lazy labeling struct
* @count: ref count of active users
* @node: rbtree position
* @rcu: rcu callback struct
* @proxy: is set to the label that replaced this label
* @hname: text representation of the label (MAYBE_NULL)
* @flags: stale and other flags - values may change under label set lock
* @secid: secid that references this label
* @size: number of entries in @ent[]
* @ent: set of profiles for label, actual size determined by @size
*/
struct aa_label {
struct kref count;
struct rb_node node;
struct rcu_head rcu;
struct aa_proxy *proxy;
__counted char *hname;
long flags;
u32 secid;
int size;
struct aa_profile *vec[];
};
#define last_error(E, FN) \
do { \
int __subE = (FN); \
if (__subE) \
(E) = __subE; \
} while (0)
#define label_isprofile(X) ((X)->flags & FLAG_PROFILE)
#define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED)
#define unconfined(X) label_unconfined(X)
#define label_is_stale(X) ((X)->flags & FLAG_STALE)
#define __label_make_stale(X) ((X)->flags |= FLAG_STALE)
#define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size))
#define labels_set(X) (&labels_ns(X)->labels)
#define labels_profile(X) ((X)->vec[(X)->size - 1])
int aa_label_next_confined(struct aa_label *l, int i);
/* for each profile in a label */
#define label_for_each(I, L, P) \
for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i))
/* assumes break/goto ended label_for_each */
#define label_for_each_cont(I, L, P) \
for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i))
#define next_comb(I, L1, L2) \
do { \
(I).j++; \
if ((I).j >= (L2)->size) { \
(I).i++; \
(I).j = 0; \
} \
} while (0)
/* for each combination of P1 in L1, and P2 in L2 */
#define label_for_each_comb(I, L1, L2, P1, P2) \
for ((I).i = (I).j = 0; \
((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \
(I) = next_comb(I, L1, L2))
#define fn_for_each_comb(L1, L2, P1, P2, FN) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \
last_error(__E, (FN)); \
} \
__E; \
})
/* for each profile that is enforcing confinement in a label */
#define label_for_each_confined(I, L, P) \
for ((I).i = aa_label_next_confined((L), 0); \
((P) = (L)->vec[(I).i]); \
(I).i = aa_label_next_confined((L), (I).i + 1))
#define label_for_each_in_merge(I, A, B, P) \
for ((I).i = (I).j = 0; \
((P) = aa_label_next_in_merge(&(I), (A), (B))); \
)
#define label_for_each_not_in_set(I, SET, SUB, P) \
for ((I).i = (I).j = 0; \
((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \
)
#define next_in_ns(i, NS, L) \
({ \
typeof(i) ___i = (i); \
while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \
(___i)++; \
(___i); \
})
#define label_for_each_in_ns(I, NS, L, P) \
for ((I).i = next_in_ns(0, (NS), (L)); \
((P) = (L)->vec[(I).i]); \
(I).i = next_in_ns((I).i + 1, (NS), (L)))
#define fn_for_each_in_ns(L, P, FN) \
({ \
struct label_it __i; \
struct aa_ns *__ns = labels_ns(L); \
int __E = 0; \
label_for_each_in_ns(__i, __ns, (L), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each_XXX(L, P, FN, ...) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each ## __VA_ARGS__(i, (L), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN)
#define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined)
#define fn_for_each2_XXX(L1, L2, P, FN, ...) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each_in_merge(L1, L2, P, FN) \
fn_for_each2_XXX((L1), (L2), P, FN, _in_merge)
#define fn_for_each_not_in_set(L1, L2, P, FN) \
fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set)
#define LABEL_MEDIATES(L, C) \
({ \
struct aa_profile *profile; \
struct label_it i; \
int ret = 0; \
label_for_each(i, (L), profile) { \
if (PROFILE_MEDIATES(profile, (C))) { \
ret = 1; \
break; \
} \
} \
ret; \
})
void aa_labelset_destroy(struct aa_labelset *ls);
void aa_labelset_init(struct aa_labelset *ls);
void __aa_labelset_update_subtree(struct aa_ns *ns);
void aa_label_free(struct aa_label *label);
void aa_label_kref(struct kref *kref);
bool aa_label_init(struct aa_label *label, int size, gfp_t gfp);
struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp);
bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub);
bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub);
struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
struct aa_label *set,
struct aa_label *sub);
bool aa_label_remove(struct aa_label *label);
struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l);
bool aa_label_replace(struct aa_label *old, struct aa_label *new);
bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old,
struct aa_label *new);
struct aa_label *aa_label_find(struct aa_label *l);
struct aa_profile *aa_label_next_in_merge(struct label_it *I,
struct aa_label *a,
struct aa_label *b);
struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b);
struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
gfp_t gfp);
bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp);
#define FLAGS_NONE 0
#define FLAG_SHOW_MODE 1
#define FLAG_VIEW_SUBNS 2
#define FLAG_HIDDEN_UNCONFINED 4
#define FLAG_ABS_ROOT 8
int aa_label_snxprint(char *str, size_t size, struct aa_ns *view,
struct aa_label *label, int flags);
int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
int flags, gfp_t gfp);
int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
gfp_t gfp);
void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp);
void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp);
void aa_label_printk(struct aa_label *label, gfp_t gfp);
struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str,
size_t n, gfp_t gfp, bool create,
bool force_stack);
struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
gfp_t gfp, bool create, bool force_stack);
static inline const char *aa_label_strn_split(const char *str, int n)
{
const char *pos;
unsigned int state;
state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos);
if (!ACCEPT_TABLE(stacksplitdfa)[state])
return NULL;
return pos - 3;
}
static inline const char *aa_label_str_split(const char *str)
{
const char *pos;
unsigned int state;
state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos);
if (!ACCEPT_TABLE(stacksplitdfa)[state])
return NULL;
return pos - 3;
}
struct aa_perms;
int aa_label_match(struct aa_profile *profile, struct aa_label *label,
unsigned int state, bool subns, u32 request,
struct aa_perms *perms);
/**
* __aa_get_label - get a reference count to uncounted label reference
* @l: reference to get a count on
*
* Returns: pointer to reference OR NULL if race is lost and reference is
* being repeated.
* Requires: lock held, and the return code MUST be checked
*/
static inline struct aa_label *__aa_get_label(struct aa_label *l)
{
if (l && kref_get_unless_zero(&l->count))
return l;
return NULL;
}
static inline struct aa_label *aa_get_label(struct aa_label *l)
{
if (l)
kref_get(&(l->count));
return l;
}
/**
* aa_get_label_rcu - increment refcount on a label that can be replaced
* @l: pointer to label that can be replaced (NOT NULL)
*
* Returns: pointer to a refcounted label.
* else NULL if no label
*/
static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l)
{
struct aa_label *c;
rcu_read_lock();
do {
c = rcu_dereference(*l);
} while (c && !kref_get_unless_zero(&c->count));
rcu_read_unlock();
return c;
}
/**
* aa_get_newest_label - find the newest version of @l
* @l: the label to check for newer versions of
*
* Returns: refcounted newest version of @l taking into account
* replacement, renames and removals
* return @l.
*/
static inline struct aa_label *aa_get_newest_label(struct aa_label *l)
{
if (!l)
return NULL;
if (label_is_stale(l)) {
struct aa_label *tmp;
AA_BUG(!l->proxy);
AA_BUG(!l->proxy->label);
/* BUG: only way this can happen is @l ref count and its
* replacement count have gone to 0 and are on their way
* to destruction. ie. we have a refcounting error
*/
tmp = aa_get_label_rcu(&l->proxy->label);
AA_BUG(!tmp);
return tmp;
}
return aa_get_label(l);
}
static inline void aa_put_label(struct aa_label *l)
{
if (l)
kref_put(&l->count, aa_label_kref);
}
struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp);
void aa_proxy_kref(struct kref *kref);
static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy)
{
if (proxy)
kref_get(&(proxy->count));
return proxy;
}
static inline void aa_put_proxy(struct aa_proxy *proxy)
{
if (proxy)
kref_put(&proxy->count, aa_proxy_kref);
}
void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new);
#endif /* __AA_LABEL_H */