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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/security/apparmor/policy_unpack.c

1448 строки
34 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* AppArmor security module
*
* This file contains AppArmor functions for unpacking policy loaded from
* userspace.
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* AppArmor uses a serialized binary format for loading policy. To find
* policy format documentation see Documentation/admin-guide/LSM/apparmor.rst
* All policy is validated before it is used.
*/
#include <asm/unaligned.h>
#include <kunit/visibility.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/zstd.h>
#include "include/apparmor.h"
#include "include/audit.h"
#include "include/cred.h"
#include "include/crypto.h"
#include "include/file.h"
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/policy_unpack.h"
#include "include/policy_compat.h"
/* audit callback for unpack fields */
static void audit_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->iface.ns) {
audit_log_format(ab, " ns=");
audit_log_untrustedstring(ab, aad(sa)->iface.ns);
}
if (aad(sa)->name) {
audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, aad(sa)->name);
}
if (aad(sa)->iface.pos)
audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos);
}
/**
* audit_iface - do audit message for policy unpacking/load/replace/remove
* @new: profile if it has been allocated (MAYBE NULL)
* @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
* @name: name of the profile being manipulated (MAYBE NULL)
* @info: any extra info about the failure (MAYBE NULL)
* @e: buffer position info
* @error: error code
*
* Returns: %0 or error
*/
static int audit_iface(struct aa_profile *new, const char *ns_name,
const char *name, const char *info, struct aa_ext *e,
int error)
{
struct aa_profile *profile = labels_profile(aa_current_raw_label());
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL);
if (e)
aad(&sa)->iface.pos = e->pos - e->start;
aad(&sa)->iface.ns = ns_name;
if (new)
aad(&sa)->name = new->base.hname;
else
aad(&sa)->name = name;
aad(&sa)->info = info;
aad(&sa)->error = error;
return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
}
void __aa_loaddata_update(struct aa_loaddata *data, long revision)
{
AA_BUG(!data);
AA_BUG(!data->ns);
AA_BUG(!mutex_is_locked(&data->ns->lock));
AA_BUG(data->revision > revision);
data->revision = revision;
if ((data->dents[AAFS_LOADDATA_REVISION])) {
d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime =
current_time(d_inode(data->dents[AAFS_LOADDATA_DIR]));
d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime =
current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION]));
}
}
bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r)
{
if (l->size != r->size)
return false;
if (l->compressed_size != r->compressed_size)
return false;
if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0)
return false;
return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0;
}
/*
* need to take the ns mutex lock which is NOT safe most places that
* put_loaddata is called, so we have to delay freeing it
*/
static void do_loaddata_free(struct work_struct *work)
{
struct aa_loaddata *d = container_of(work, struct aa_loaddata, work);
struct aa_ns *ns = aa_get_ns(d->ns);
if (ns) {
mutex_lock_nested(&ns->lock, ns->level);
__aa_fs_remove_rawdata(d);
mutex_unlock(&ns->lock);
aa_put_ns(ns);
}
kfree_sensitive(d->hash);
kfree_sensitive(d->name);
kvfree(d->data);
kfree_sensitive(d);
}
void aa_loaddata_kref(struct kref *kref)
{
struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count);
if (d) {
INIT_WORK(&d->work, do_loaddata_free);
schedule_work(&d->work);
}
}
struct aa_loaddata *aa_loaddata_alloc(size_t size)
{
struct aa_loaddata *d;
d = kzalloc(sizeof(*d), GFP_KERNEL);
if (d == NULL)
return ERR_PTR(-ENOMEM);
d->data = kvzalloc(size, GFP_KERNEL);
if (!d->data) {
kfree(d);
return ERR_PTR(-ENOMEM);
}
kref_init(&d->count);
INIT_LIST_HEAD(&d->list);
return d;
}
/* test if read will be in packed data bounds */
VISIBLE_IF_KUNIT bool aa_inbounds(struct aa_ext *e, size_t size)
{
return (size <= e->end - e->pos);
}
EXPORT_SYMBOL_IF_KUNIT(aa_inbounds);
/**
* aa_unpack_u16_chunk - test and do bounds checking for a u16 size based chunk
* @e: serialized data read head (NOT NULL)
* @chunk: start address for chunk of data (NOT NULL)
*
* Returns: the size of chunk found with the read head at the end of the chunk.
*/
VISIBLE_IF_KUNIT size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk)
{
size_t size = 0;
void *pos = e->pos;
if (!aa_inbounds(e, sizeof(u16)))
goto fail;
size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
e->pos += sizeof(__le16);
if (!aa_inbounds(e, size))
goto fail;
*chunk = e->pos;
e->pos += size;
return size;
fail:
e->pos = pos;
return 0;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u16_chunk);
/* unpack control byte */
VISIBLE_IF_KUNIT bool aa_unpack_X(struct aa_ext *e, enum aa_code code)
{
if (!aa_inbounds(e, 1))
return false;
if (*(u8 *) e->pos != code)
return false;
e->pos++;
return true;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_X);
/**
* aa_unpack_nameX - check is the next element is of type X with a name of @name
* @e: serialized data extent information (NOT NULL)
* @code: type code
* @name: name to match to the serialized element. (MAYBE NULL)
*
* check that the next serialized data element is of type X and has a tag
* name @name. If @name is specified then there must be a matching
* name element in the stream. If @name is NULL any name element will be
* skipped and only the typecode will be tested.
*
* Returns true on success (both type code and name tests match) and the read
* head is advanced past the headers
*
* Returns: false if either match fails, the read head does not move
*/
VISIBLE_IF_KUNIT bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
{
/*
* May need to reset pos if name or type doesn't match
*/
void *pos = e->pos;
/*
* Check for presence of a tagname, and if present name size
* AA_NAME tag value is a u16.
*/
if (aa_unpack_X(e, AA_NAME)) {
char *tag = NULL;
size_t size = aa_unpack_u16_chunk(e, &tag);
/* if a name is specified it must match. otherwise skip tag */
if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag)))
goto fail;
} else if (name) {
/* if a name is specified and there is no name tag fail */
goto fail;
}
/* now check if type code matches */
if (aa_unpack_X(e, code))
return true;
fail:
e->pos = pos;
return false;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_nameX);
static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_U8, name)) {
if (!aa_inbounds(e, sizeof(u8)))
goto fail;
if (data)
*data = *((u8 *)e->pos);
e->pos += sizeof(u8);
return true;
}
fail:
e->pos = pos;
return false;
}
VISIBLE_IF_KUNIT bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_U32, name)) {
if (!aa_inbounds(e, sizeof(u32)))
goto fail;
if (data)
*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
e->pos += sizeof(u32);
return true;
}
fail:
e->pos = pos;
return false;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u32);
VISIBLE_IF_KUNIT bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_U64, name)) {
if (!aa_inbounds(e, sizeof(u64)))
goto fail;
if (data)
*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
e->pos += sizeof(u64);
return true;
}
fail:
e->pos = pos;
return false;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u64);
static bool aa_unpack_cap_low(struct aa_ext *e, kernel_cap_t *data, const char *name)
{
u32 val;
if (!aa_unpack_u32(e, &val, name))
return false;
data->val = val;
return true;
}
static bool aa_unpack_cap_high(struct aa_ext *e, kernel_cap_t *data, const char *name)
{
u32 val;
if (!aa_unpack_u32(e, &val, name))
return false;
data->val = (u32)data->val | ((u64)val << 32);
return true;
}
VISIBLE_IF_KUNIT bool aa_unpack_array(struct aa_ext *e, const char *name, u16 *size)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_ARRAY, name)) {
if (!aa_inbounds(e, sizeof(u16)))
goto fail;
*size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
e->pos += sizeof(u16);
return true;
}
fail:
e->pos = pos;
return false;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_array);
VISIBLE_IF_KUNIT size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_BLOB, name)) {
u32 size;
if (!aa_inbounds(e, sizeof(u32)))
goto fail;
size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
e->pos += sizeof(u32);
if (aa_inbounds(e, (size_t) size)) {
*blob = e->pos;
e->pos += size;
return size;
}
}
fail:
e->pos = pos;
return 0;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_blob);
VISIBLE_IF_KUNIT int aa_unpack_str(struct aa_ext *e, const char **string, const char *name)
{
char *src_str;
size_t size = 0;
void *pos = e->pos;
*string = NULL;
if (aa_unpack_nameX(e, AA_STRING, name)) {
size = aa_unpack_u16_chunk(e, &src_str);
if (size) {
/* strings are null terminated, length is size - 1 */
if (src_str[size - 1] != 0)
goto fail;
*string = src_str;
return size;
}
}
fail:
e->pos = pos;
return 0;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_str);
VISIBLE_IF_KUNIT int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name)
{
const char *tmp;
void *pos = e->pos;
int res = aa_unpack_str(e, &tmp, name);
*string = NULL;
if (!res)
return 0;
*string = kmemdup(tmp, res, GFP_KERNEL);
if (!*string) {
e->pos = pos;
return 0;
}
return res;
}
EXPORT_SYMBOL_IF_KUNIT(aa_unpack_strdup);
/**
* unpack_dfa - unpack a file rule dfa
* @e: serialized data extent information (NOT NULL)
* @flags: dfa flags to check
*
* returns dfa or ERR_PTR or NULL if no dfa
*/
static struct aa_dfa *unpack_dfa(struct aa_ext *e, int flags)
{
char *blob = NULL;
size_t size;
struct aa_dfa *dfa = NULL;
size = aa_unpack_blob(e, &blob, "aadfa");
if (size) {
/*
* The dfa is aligned with in the blob to 8 bytes
* from the beginning of the stream.
* alignment adjust needed by dfa unpack
*/
size_t sz = blob - (char *) e->start -
((e->pos - e->start) & 7);
size_t pad = ALIGN(sz, 8) - sz;
if (aa_g_paranoid_load)
flags |= DFA_FLAG_VERIFY_STATES;
dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
if (IS_ERR(dfa))
return dfa;
}
return dfa;
}
/**
* unpack_trans_table - unpack a profile transition table
* @e: serialized data extent information (NOT NULL)
* @table: str table to unpack to (NOT NULL)
*
* Returns: true if table successfully unpacked or not present
*/
static bool unpack_trans_table(struct aa_ext *e, struct aa_str_table *strs)
{
void *saved_pos = e->pos;
char **table = NULL;
/* exec table is optional */
if (aa_unpack_nameX(e, AA_STRUCT, "xtable")) {
u16 size;
int i;
if (!aa_unpack_array(e, NULL, &size))
/*
* Note: index into trans table array is a max
* of 2^24, but unpack array can only unpack
* an array of 2^16 in size atm so no need
* for size check here
*/
goto fail;
table = kcalloc(size, sizeof(char *), GFP_KERNEL);
if (!table)
goto fail;
for (i = 0; i < size; i++) {
char *str;
int c, j, pos, size2 = aa_unpack_strdup(e, &str, NULL);
/* aa_unpack_strdup verifies that the last character is
* null termination byte.
*/
if (!size2)
goto fail;
table[i] = str;
/* verify that name doesn't start with space */
if (isspace(*str))
goto fail;
/* count internal # of internal \0 */
for (c = j = 0; j < size2 - 1; j++) {
if (!str[j]) {
pos = j;
c++;
}
}
if (*str == ':') {
/* first character after : must be valid */
if (!str[1])
goto fail;
/* beginning with : requires an embedded \0,
* verify that exactly 1 internal \0 exists
* trailing \0 already verified by aa_unpack_strdup
*
* convert \0 back to : for label_parse
*/
if (c == 1)
str[pos] = ':';
else if (c > 1)
goto fail;
} else if (c)
/* fail - all other cases with embedded \0 */
goto fail;
}
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
strs->table = table;
strs->size = size;
}
return true;
fail:
kfree_sensitive(table);
e->pos = saved_pos;
return false;
}
static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile)
{
void *pos = e->pos;
if (aa_unpack_nameX(e, AA_STRUCT, "xattrs")) {
u16 size;
int i;
if (!aa_unpack_array(e, NULL, &size))
goto fail;
profile->attach.xattr_count = size;
profile->attach.xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL);
if (!profile->attach.xattrs)
goto fail;
for (i = 0; i < size; i++) {
if (!aa_unpack_strdup(e, &profile->attach.xattrs[i], NULL))
goto fail;
}
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
}
return true;
fail:
e->pos = pos;
return false;
}
static bool unpack_secmark(struct aa_ext *e, struct aa_ruleset *rules)
{
void *pos = e->pos;
u16 size;
int i;
if (aa_unpack_nameX(e, AA_STRUCT, "secmark")) {
if (!aa_unpack_array(e, NULL, &size))
goto fail;
rules->secmark = kcalloc(size, sizeof(struct aa_secmark),
GFP_KERNEL);
if (!rules->secmark)
goto fail;
rules->secmark_count = size;
for (i = 0; i < size; i++) {
if (!unpack_u8(e, &rules->secmark[i].audit, NULL))
goto fail;
if (!unpack_u8(e, &rules->secmark[i].deny, NULL))
goto fail;
if (!aa_unpack_strdup(e, &rules->secmark[i].label, NULL))
goto fail;
}
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
}
return true;
fail:
if (rules->secmark) {
for (i = 0; i < size; i++)
kfree(rules->secmark[i].label);
kfree(rules->secmark);
rules->secmark_count = 0;
rules->secmark = NULL;
}
e->pos = pos;
return false;
}
static bool unpack_rlimits(struct aa_ext *e, struct aa_ruleset *rules)
{
void *pos = e->pos;
/* rlimits are optional */
if (aa_unpack_nameX(e, AA_STRUCT, "rlimits")) {
u16 size;
int i;
u32 tmp = 0;
if (!aa_unpack_u32(e, &tmp, NULL))
goto fail;
rules->rlimits.mask = tmp;
if (!aa_unpack_array(e, NULL, &size) ||
size > RLIM_NLIMITS)
goto fail;
for (i = 0; i < size; i++) {
u64 tmp2 = 0;
int a = aa_map_resource(i);
if (!aa_unpack_u64(e, &tmp2, NULL))
goto fail;
rules->rlimits.limits[a].rlim_max = tmp2;
}
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
}
return true;
fail:
e->pos = pos;
return false;
}
static bool unpack_perm(struct aa_ext *e, u32 version, struct aa_perms *perm)
{
if (version != 1)
return false;
return aa_unpack_u32(e, &perm->allow, NULL) &&
aa_unpack_u32(e, &perm->allow, NULL) &&
aa_unpack_u32(e, &perm->deny, NULL) &&
aa_unpack_u32(e, &perm->subtree, NULL) &&
aa_unpack_u32(e, &perm->cond, NULL) &&
aa_unpack_u32(e, &perm->kill, NULL) &&
aa_unpack_u32(e, &perm->complain, NULL) &&
aa_unpack_u32(e, &perm->prompt, NULL) &&
aa_unpack_u32(e, &perm->audit, NULL) &&
aa_unpack_u32(e, &perm->quiet, NULL) &&
aa_unpack_u32(e, &perm->hide, NULL) &&
aa_unpack_u32(e, &perm->xindex, NULL) &&
aa_unpack_u32(e, &perm->tag, NULL) &&
aa_unpack_u32(e, &perm->label, NULL);
}
static ssize_t unpack_perms_table(struct aa_ext *e, struct aa_perms **perms)
{
void *pos = e->pos;
u16 size = 0;
AA_BUG(!perms);
/*
* policy perms are optional, in which case perms are embedded
* in the dfa accept table
*/
if (aa_unpack_nameX(e, AA_STRUCT, "perms")) {
int i;
u32 version;
if (!aa_unpack_u32(e, &version, "version"))
goto fail_reset;
if (!aa_unpack_array(e, NULL, &size))
goto fail_reset;
*perms = kcalloc(size, sizeof(struct aa_perms), GFP_KERNEL);
if (!*perms)
goto fail_reset;
for (i = 0; i < size; i++) {
if (!unpack_perm(e, version, &(*perms)[i]))
goto fail;
}
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
} else
*perms = NULL;
return size;
fail:
kfree(*perms);
fail_reset:
e->pos = pos;
return -EPROTO;
}
static int unpack_pdb(struct aa_ext *e, struct aa_policydb *policy,
bool required_dfa, bool required_trans,
const char **info)
{
void *pos = e->pos;
int i, flags, error = -EPROTO;
ssize_t size;
size = unpack_perms_table(e, &policy->perms);
if (size < 0) {
error = size;
policy->perms = NULL;
*info = "failed to unpack - perms";
goto fail;
}
policy->size = size;
if (policy->perms) {
/* perms table present accept is index */
flags = TO_ACCEPT1_FLAG(YYTD_DATA32);
} else {
/* packed perms in accept1 and accept2 */
flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
TO_ACCEPT2_FLAG(YYTD_DATA32);
}
policy->dfa = unpack_dfa(e, flags);
if (IS_ERR(policy->dfa)) {
error = PTR_ERR(policy->dfa);
policy->dfa = NULL;
*info = "failed to unpack - dfa";
goto fail;
} else if (!policy->dfa) {
if (required_dfa) {
*info = "missing required dfa";
goto fail;
}
goto out;
}
/*
* only unpack the following if a dfa is present
*
* sadly start was given different names for file and policydb
* but since it is optional we can try both
*/
if (!aa_unpack_u32(e, &policy->start[0], "start"))
/* default start state */
policy->start[0] = DFA_START;
if (!aa_unpack_u32(e, &policy->start[AA_CLASS_FILE], "dfa_start")) {
/* default start state for xmatch and file dfa */
policy->start[AA_CLASS_FILE] = DFA_START;
} /* setup class index */
for (i = AA_CLASS_FILE + 1; i <= AA_CLASS_LAST; i++) {
policy->start[i] = aa_dfa_next(policy->dfa, policy->start[0],
i);
}
if (!unpack_trans_table(e, &policy->trans) && required_trans) {
*info = "failed to unpack profile transition table";
goto fail;
}
/* TODO: move compat mapping here, requires dfa merging first */
/* TODO: move verify here, it has to be done after compat mappings */
out:
return 0;
fail:
e->pos = pos;
return error;
}
static u32 strhash(const void *data, u32 len, u32 seed)
{
const char * const *key = data;
return jhash(*key, strlen(*key), seed);
}
static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
{
const struct aa_data *data = obj;
const char * const *key = arg->key;
return strcmp(data->key, *key);
}
/**
* unpack_profile - unpack a serialized profile
* @e: serialized data extent information (NOT NULL)
* @ns_name: pointer of newly allocated copy of %NULL in case of error
*
* NOTE: unpack profile sets audit struct if there is a failure
*/
static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
{
struct aa_ruleset *rules;
struct aa_profile *profile = NULL;
const char *tmpname, *tmpns = NULL, *name = NULL;
const char *info = "failed to unpack profile";
size_t ns_len;
struct rhashtable_params params = { 0 };
char *key = NULL;
struct aa_data *data;
int error = -EPROTO;
kernel_cap_t tmpcap;
u32 tmp;
*ns_name = NULL;
/* check that we have the right struct being passed */
if (!aa_unpack_nameX(e, AA_STRUCT, "profile"))
goto fail;
if (!aa_unpack_str(e, &name, NULL))
goto fail;
if (*name == '\0')
goto fail;
tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
if (tmpns) {
*ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
if (!*ns_name) {
info = "out of memory";
error = -ENOMEM;
goto fail;
}
name = tmpname;
}
profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
if (!profile) {
info = "out of memory";
error = -ENOMEM;
goto fail;
}
rules = list_first_entry(&profile->rules, typeof(*rules), list);
/* profile renaming is optional */
(void) aa_unpack_str(e, &profile->rename, "rename");
/* attachment string is optional */
(void) aa_unpack_str(e, &profile->attach.xmatch_str, "attach");
/* xmatch is optional and may be NULL */
error = unpack_pdb(e, &profile->attach.xmatch, false, false, &info);
if (error) {
info = "bad xmatch";
goto fail;
}
/* neither xmatch_len not xmatch_perms are optional if xmatch is set */
if (profile->attach.xmatch.dfa) {
if (!aa_unpack_u32(e, &tmp, NULL)) {
info = "missing xmatch len";
goto fail;
}
profile->attach.xmatch_len = tmp;
profile->attach.xmatch.start[AA_CLASS_XMATCH] = DFA_START;
error = aa_compat_map_xmatch(&profile->attach.xmatch);
if (error) {
info = "failed to convert xmatch permission table";
goto fail;
}
}
/* disconnected attachment string is optional */
(void) aa_unpack_str(e, &profile->disconnected, "disconnected");
/* per profile debug flags (complain, audit) */
if (!aa_unpack_nameX(e, AA_STRUCT, "flags")) {
info = "profile missing flags";
goto fail;
}
info = "failed to unpack profile flags";
if (!aa_unpack_u32(e, &tmp, NULL))
goto fail;
if (tmp & PACKED_FLAG_HAT)
profile->label.flags |= FLAG_HAT;
if (tmp & PACKED_FLAG_DEBUG1)
profile->label.flags |= FLAG_DEBUG1;
if (tmp & PACKED_FLAG_DEBUG2)
profile->label.flags |= FLAG_DEBUG2;
if (!aa_unpack_u32(e, &tmp, NULL))
goto fail;
if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) {
profile->mode = APPARMOR_COMPLAIN;
} else if (tmp == PACKED_MODE_ENFORCE) {
profile->mode = APPARMOR_ENFORCE;
} else if (tmp == PACKED_MODE_KILL) {
profile->mode = APPARMOR_KILL;
} else if (tmp == PACKED_MODE_UNCONFINED) {
profile->mode = APPARMOR_UNCONFINED;
profile->label.flags |= FLAG_UNCONFINED;
} else if (tmp == PACKED_MODE_USER) {
profile->mode = APPARMOR_USER;
} else {
goto fail;
}
if (!aa_unpack_u32(e, &tmp, NULL))
goto fail;
if (tmp)
profile->audit = AUDIT_ALL;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
/* path_flags is optional */
if (aa_unpack_u32(e, &profile->path_flags, "path_flags"))
profile->path_flags |= profile->label.flags &
PATH_MEDIATE_DELETED;
else
/* set a default value if path_flags field is not present */
profile->path_flags = PATH_MEDIATE_DELETED;
info = "failed to unpack profile capabilities";
if (!aa_unpack_cap_low(e, &rules->caps.allow, NULL))
goto fail;
if (!aa_unpack_cap_low(e, &rules->caps.audit, NULL))
goto fail;
if (!aa_unpack_cap_low(e, &rules->caps.quiet, NULL))
goto fail;
if (!aa_unpack_cap_low(e, &tmpcap, NULL))
goto fail;
info = "failed to unpack upper profile capabilities";
if (aa_unpack_nameX(e, AA_STRUCT, "caps64")) {
/* optional upper half of 64 bit caps */
if (!aa_unpack_cap_high(e, &rules->caps.allow, NULL))
goto fail;
if (!aa_unpack_cap_high(e, &rules->caps.audit, NULL))
goto fail;
if (!aa_unpack_cap_high(e, &rules->caps.quiet, NULL))
goto fail;
if (!aa_unpack_cap_high(e, &tmpcap, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
}
info = "failed to unpack extended profile capabilities";
if (aa_unpack_nameX(e, AA_STRUCT, "capsx")) {
/* optional extended caps mediation mask */
if (!aa_unpack_cap_low(e, &rules->caps.extended, NULL))
goto fail;
if (!aa_unpack_cap_high(e, &rules->caps.extended, NULL))
goto fail;
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
}
if (!unpack_xattrs(e, profile)) {
info = "failed to unpack profile xattrs";
goto fail;
}
if (!unpack_rlimits(e, rules)) {
info = "failed to unpack profile rlimits";
goto fail;
}
if (!unpack_secmark(e, rules)) {
info = "failed to unpack profile secmark rules";
goto fail;
}
if (aa_unpack_nameX(e, AA_STRUCT, "policydb")) {
/* generic policy dfa - optional and may be NULL */
info = "failed to unpack policydb";
error = unpack_pdb(e, &rules->policy, true, false,
&info);
if (error)
goto fail;
/* Fixup: drop when we get rid of start array */
if (aa_dfa_next(rules->policy.dfa, rules->policy.start[0],
AA_CLASS_FILE))
rules->policy.start[AA_CLASS_FILE] =
aa_dfa_next(rules->policy.dfa,
rules->policy.start[0],
AA_CLASS_FILE);
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
goto fail;
error = aa_compat_map_policy(&rules->policy, e->version);
if (error) {
info = "failed to remap policydb permission table";
goto fail;
}
} else
rules->policy.dfa = aa_get_dfa(nulldfa);
/* get file rules */
error = unpack_pdb(e, &rules->file, false, true, &info);
if (error) {
goto fail;
} else if (rules->file.dfa) {
error = aa_compat_map_file(&rules->file);
if (error) {
info = "failed to remap file permission table";
goto fail;
}
} else if (rules->policy.dfa &&
rules->policy.start[AA_CLASS_FILE]) {
rules->file.dfa = aa_get_dfa(rules->policy.dfa);
rules->file.start[AA_CLASS_FILE] = rules->policy.start[AA_CLASS_FILE];
} else
rules->file.dfa = aa_get_dfa(nulldfa);
error = -EPROTO;
if (aa_unpack_nameX(e, AA_STRUCT, "data")) {
info = "out of memory";
profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL);
if (!profile->data) {
error = -ENOMEM;
goto fail;
}
params.nelem_hint = 3;
params.key_len = sizeof(void *);
params.key_offset = offsetof(struct aa_data, key);
params.head_offset = offsetof(struct aa_data, head);
params.hashfn = strhash;
params.obj_cmpfn = datacmp;
if (rhashtable_init(profile->data, &params)) {
info = "failed to init key, value hash table";
goto fail;
}
while (aa_unpack_strdup(e, &key, NULL)) {
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
kfree_sensitive(key);
error = -ENOMEM;
goto fail;
}
data->key = key;
data->size = aa_unpack_blob(e, &data->data, NULL);
data->data = kvmemdup(data->data, data->size, GFP_KERNEL);
if (data->size && !data->data) {
kfree_sensitive(data->key);
kfree_sensitive(data);
error = -ENOMEM;
goto fail;
}
rhashtable_insert_fast(profile->data, &data->head,
profile->data->p);
}
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) {
info = "failed to unpack end of key, value data table";
goto fail;
}
}
if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) {
info = "failed to unpack end of profile";
goto fail;
}
return profile;
fail:
if (error == 0)
/* default error covers most cases */
error = -EPROTO;
if (*ns_name) {
kfree(*ns_name);
*ns_name = NULL;
}
if (profile)
name = NULL;
else if (!name)
name = "unknown";
audit_iface(profile, NULL, name, info, e, error);
aa_free_profile(profile);
return ERR_PTR(error);
}
/**
* verify_header - unpack serialized stream header
* @e: serialized data read head (NOT NULL)
* @required: whether the header is required or optional
* @ns: Returns - namespace if one is specified else NULL (NOT NULL)
*
* Returns: error or 0 if header is good
*/
static int verify_header(struct aa_ext *e, int required, const char **ns)
{
int error = -EPROTONOSUPPORT;
const char *name = NULL;
*ns = NULL;
/* get the interface version */
if (!aa_unpack_u32(e, &e->version, "version")) {
if (required) {
audit_iface(NULL, NULL, NULL, "invalid profile format",
e, error);
return error;
}
}
/* Check that the interface version is currently supported.
* if not specified use previous version
* Mask off everything that is not kernel abi version
*/
if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v9)) {
audit_iface(NULL, NULL, NULL, "unsupported interface version",
e, error);
return error;
}
/* read the namespace if present */
if (aa_unpack_str(e, &name, "namespace")) {
if (*name == '\0') {
audit_iface(NULL, NULL, NULL, "invalid namespace name",
e, error);
return error;
}
if (*ns && strcmp(*ns, name)) {
audit_iface(NULL, NULL, NULL, "invalid ns change", e,
error);
} else if (!*ns) {
*ns = kstrdup(name, GFP_KERNEL);
if (!*ns)
return -ENOMEM;
}
}
return 0;
}
static bool verify_xindex(int xindex, int table_size)
{
int index, xtype;
xtype = xindex & AA_X_TYPE_MASK;
index = xindex & AA_X_INDEX_MASK;
if (xtype == AA_X_TABLE && index >= table_size)
return false;
return true;
}
/* verify dfa xindexes are in range of transition tables */
static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
{
int i;
for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
if (!verify_xindex(ACCEPT_TABLE(dfa)[i], table_size))
return false;
}
return true;
}
static bool verify_perm(struct aa_perms *perm)
{
/* TODO: allow option to just force the perms into a valid state */
if (perm->allow & perm->deny)
return false;
if (perm->subtree & ~perm->allow)
return false;
if (perm->cond & (perm->allow | perm->deny))
return false;
if (perm->kill & perm->allow)
return false;
if (perm->complain & (perm->allow | perm->deny))
return false;
if (perm->prompt & (perm->allow | perm->deny))
return false;
if (perm->complain & perm->prompt)
return false;
if (perm->hide & perm->allow)
return false;
return true;
}
static bool verify_perms(struct aa_policydb *pdb)
{
int i;
for (i = 0; i < pdb->size; i++) {
if (!verify_perm(&pdb->perms[i]))
return false;
/* verify indexes into str table */
if (pdb->perms[i].xindex >= pdb->trans.size)
return false;
if (pdb->perms[i].tag >= pdb->trans.size)
return false;
if (pdb->perms[i].label >= pdb->trans.size)
return false;
}
return true;
}
/**
* verify_profile - Do post unpack analysis to verify profile consistency
* @profile: profile to verify (NOT NULL)
*
* Returns: 0 if passes verification else error
*
* This verification is post any unpack mapping or changes
*/
static int verify_profile(struct aa_profile *profile)
{
struct aa_ruleset *rules = list_first_entry(&profile->rules,
typeof(*rules), list);
if (!rules)
return 0;
if ((rules->file.dfa && !verify_dfa_xindex(rules->file.dfa,
rules->file.trans.size)) ||
(rules->policy.dfa &&
!verify_dfa_xindex(rules->policy.dfa, rules->policy.trans.size))) {
audit_iface(profile, NULL, NULL,
"Unpack: Invalid named transition", NULL, -EPROTO);
return -EPROTO;
}
if (!verify_perms(&rules->file)) {
audit_iface(profile, NULL, NULL,
"Unpack: Invalid perm index", NULL, -EPROTO);
return -EPROTO;
}
if (!verify_perms(&rules->policy)) {
audit_iface(profile, NULL, NULL,
"Unpack: Invalid perm index", NULL, -EPROTO);
return -EPROTO;
}
if (!verify_perms(&profile->attach.xmatch)) {
audit_iface(profile, NULL, NULL,
"Unpack: Invalid perm index", NULL, -EPROTO);
return -EPROTO;
}
return 0;
}
void aa_load_ent_free(struct aa_load_ent *ent)
{
if (ent) {
aa_put_profile(ent->rename);
aa_put_profile(ent->old);
aa_put_profile(ent->new);
kfree(ent->ns_name);
kfree_sensitive(ent);
}
}
struct aa_load_ent *aa_load_ent_alloc(void)
{
struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
if (ent)
INIT_LIST_HEAD(&ent->list);
return ent;
}
static int compress_zstd(const char *src, size_t slen, char **dst, size_t *dlen)
{
#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
const zstd_parameters params =
zstd_get_params(aa_g_rawdata_compression_level, slen);
const size_t wksp_len = zstd_cctx_workspace_bound(&params.cParams);
void *wksp = NULL;
zstd_cctx *ctx = NULL;
size_t out_len = zstd_compress_bound(slen);
void *out = NULL;
int ret = 0;
out = kvzalloc(out_len, GFP_KERNEL);
if (!out) {
ret = -ENOMEM;
goto cleanup;
}
wksp = kvzalloc(wksp_len, GFP_KERNEL);
if (!wksp) {
ret = -ENOMEM;
goto cleanup;
}
ctx = zstd_init_cctx(wksp, wksp_len);
if (!ctx) {
ret = -EINVAL;
goto cleanup;
}
out_len = zstd_compress_cctx(ctx, out, out_len, src, slen, &params);
if (zstd_is_error(out_len) || out_len >= slen) {
ret = -EINVAL;
goto cleanup;
}
if (is_vmalloc_addr(out)) {
*dst = kvzalloc(out_len, GFP_KERNEL);
if (*dst) {
memcpy(*dst, out, out_len);
kvfree(out);
out = NULL;
}
} else {
/*
* If the staging buffer was kmalloc'd, then using krealloc is
* probably going to be faster. The destination buffer will
* always be smaller, so it's just shrunk, avoiding a memcpy
*/
*dst = krealloc(out, out_len, GFP_KERNEL);
}
if (!*dst) {
ret = -ENOMEM;
goto cleanup;
}
*dlen = out_len;
cleanup:
if (ret) {
kvfree(out);
*dst = NULL;
}
kvfree(wksp);
return ret;
#else
*dlen = slen;
return 0;
#endif
}
static int compress_loaddata(struct aa_loaddata *data)
{
AA_BUG(data->compressed_size > 0);
/*
* Shortcut the no compression case, else we increase the amount of
* storage required by a small amount
*/
if (aa_g_rawdata_compression_level != 0) {
void *udata = data->data;
int error = compress_zstd(udata, data->size, &data->data,
&data->compressed_size);
if (error) {
data->compressed_size = data->size;
return error;
}
if (udata != data->data)
kvfree(udata);
} else
data->compressed_size = data->size;
return 0;
}
/**
* aa_unpack - unpack packed binary profile(s) data loaded from user space
* @udata: user data copied to kmem (NOT NULL)
* @lh: list to place unpacked profiles in a aa_repl_ws
* @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
*
* Unpack user data and return refcounted allocated profile(s) stored in
* @lh in order of discovery, with the list chain stored in base.list
* or error
*
* Returns: profile(s) on @lh else error pointer if fails to unpack
*/
int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
const char **ns)
{
struct aa_load_ent *tmp, *ent;
struct aa_profile *profile = NULL;
char *ns_name = NULL;
int error;
struct aa_ext e = {
.start = udata->data,
.end = udata->data + udata->size,
.pos = udata->data,
};
*ns = NULL;
while (e.pos < e.end) {
void *start;
error = verify_header(&e, e.pos == e.start, ns);
if (error)
goto fail;
start = e.pos;
profile = unpack_profile(&e, &ns_name);
if (IS_ERR(profile)) {
error = PTR_ERR(profile);
goto fail;
}
error = verify_profile(profile);
if (error)
goto fail_profile;
if (aa_g_hash_policy)
error = aa_calc_profile_hash(profile, e.version, start,
e.pos - start);
if (error)
goto fail_profile;
ent = aa_load_ent_alloc();
if (!ent) {
error = -ENOMEM;
goto fail_profile;
}
ent->new = profile;
ent->ns_name = ns_name;
ns_name = NULL;
list_add_tail(&ent->list, lh);
}
udata->abi = e.version & K_ABI_MASK;
if (aa_g_hash_policy) {
udata->hash = aa_calc_hash(udata->data, udata->size);
if (IS_ERR(udata->hash)) {
error = PTR_ERR(udata->hash);
udata->hash = NULL;
goto fail;
}
}
if (aa_g_export_binary) {
error = compress_loaddata(udata);
if (error)
goto fail;
}
return 0;
fail_profile:
kfree(ns_name);
aa_put_profile(profile);
fail:
list_for_each_entry_safe(ent, tmp, lh, list) {
list_del_init(&ent->list);
aa_load_ent_free(ent);
}
return error;
}
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