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OpenCloudOS-Kernel/security/tomoyo/audit.c

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// SPDX-License-Identifier: GPL-2.0
/*
* security/tomoyo/audit.c
*
* Copyright (C) 2005-2011 NTT DATA CORPORATION
*/
#include "common.h"
#include <linux/slab.h>
/**
* tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
*
* @bprm: Pointer to "struct linux_binprm".
* @dump: Pointer to "struct tomoyo_page_dump".
*
* Returns the contents of @bprm on success, NULL otherwise.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_bprm(struct linux_binprm *bprm,
struct tomoyo_page_dump *dump)
{
static const int tomoyo_buffer_len = 4096 * 2;
char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
char *cp;
char *last_start;
int len;
unsigned long pos = bprm->p;
int offset = pos % PAGE_SIZE;
int argv_count = bprm->argc;
int envp_count = bprm->envc;
bool truncated = false;
if (!buffer)
return NULL;
len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
cp = buffer + len;
if (!argv_count) {
memmove(cp, "} envp[]={ ", 11);
cp += 11;
}
last_start = cp;
while (argv_count || envp_count) {
if (!tomoyo_dump_page(bprm, pos, dump))
goto out;
pos += PAGE_SIZE - offset;
/* Read. */
while (offset < PAGE_SIZE) {
const char *kaddr = dump->data;
const unsigned char c = kaddr[offset++];
if (cp == last_start)
*cp++ = '"';
if (cp >= buffer + tomoyo_buffer_len - 32) {
/* Reserve some room for "..." string. */
truncated = true;
} else if (c == '\\') {
*cp++ = '\\';
*cp++ = '\\';
} else if (c > ' ' && c < 127) {
*cp++ = c;
} else if (!c) {
*cp++ = '"';
*cp++ = ' ';
last_start = cp;
} else {
*cp++ = '\\';
*cp++ = (c >> 6) + '0';
*cp++ = ((c >> 3) & 7) + '0';
*cp++ = (c & 7) + '0';
}
if (c)
continue;
if (argv_count) {
if (--argv_count == 0) {
if (truncated) {
cp = last_start;
memmove(cp, "... ", 4);
cp += 4;
}
memmove(cp, "} envp[]={ ", 11);
cp += 11;
last_start = cp;
truncated = false;
}
} else if (envp_count) {
if (--envp_count == 0) {
if (truncated) {
cp = last_start;
memmove(cp, "... ", 4);
cp += 4;
}
}
}
if (!argv_count && !envp_count)
break;
}
offset = 0;
}
*cp++ = '}';
*cp = '\0';
return buffer;
out:
snprintf(buffer, tomoyo_buffer_len - 1,
"argv[]={ ... } envp[]= { ... }");
return buffer;
}
/**
* tomoyo_filetype - Get string representation of file type.
*
* @mode: Mode value for stat().
*
* Returns file type string.
*/
static inline const char *tomoyo_filetype(const umode_t mode)
{
switch (mode & S_IFMT) {
case S_IFREG:
case 0:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
case S_IFDIR:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
case S_IFLNK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
case S_IFIFO:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
case S_IFSOCK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
case S_IFBLK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
case S_IFCHR:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
}
return "unknown"; /* This should not happen. */
}
/**
* tomoyo_print_header - Get header line of audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
*
* Returns string representation.
*
* This function uses kmalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
struct tomoyo_time stamp;
const pid_t gpid = task_pid_nr(current);
struct tomoyo_obj_info *obj = r->obj;
static const int tomoyo_buffer_len = 4096;
char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
int pos;
u8 i;
if (!buffer)
return NULL;
tomoyo_convert_time(ktime_get_real_seconds(), &stamp);
pos = snprintf(buffer, tomoyo_buffer_len - 1,
"#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s granted=%s (global-pid=%u) task={ pid=%u ppid=%u uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }",
stamp.year, stamp.month, stamp.day, stamp.hour,
stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode],
str_yes_no(r->granted), gpid, tomoyo_sys_getpid(),
tomoyo_sys_getppid(),
from_kuid(&init_user_ns, current_uid()),
from_kgid(&init_user_ns, current_gid()),
from_kuid(&init_user_ns, current_euid()),
from_kgid(&init_user_ns, current_egid()),
from_kuid(&init_user_ns, current_suid()),
from_kgid(&init_user_ns, current_sgid()),
from_kuid(&init_user_ns, current_fsuid()),
from_kgid(&init_user_ns, current_fsgid()));
if (!obj)
goto no_obj_info;
if (!obj->validate_done) {
tomoyo_get_attributes(obj);
obj->validate_done = true;
}
for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
struct tomoyo_mini_stat *stat;
unsigned int dev;
umode_t mode;
if (!obj->stat_valid[i])
continue;
stat = &obj->stat[i];
dev = stat->dev;
mode = stat->mode;
if (i & 1) {
pos += snprintf(buffer + pos,
tomoyo_buffer_len - 1 - pos,
" path%u.parent={ uid=%u gid=%u ino=%lu perm=0%o }",
(i >> 1) + 1,
from_kuid(&init_user_ns, stat->uid),
from_kgid(&init_user_ns, stat->gid),
(unsigned long)stat->ino,
stat->mode & S_IALLUGO);
continue;
}
pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
" path%u={ uid=%u gid=%u ino=%lu major=%u minor=%u perm=0%o type=%s",
(i >> 1) + 1,
from_kuid(&init_user_ns, stat->uid),
from_kgid(&init_user_ns, stat->gid),
(unsigned long)stat->ino,
MAJOR(dev), MINOR(dev),
mode & S_IALLUGO, tomoyo_filetype(mode));
if (S_ISCHR(mode) || S_ISBLK(mode)) {
dev = stat->rdev;
pos += snprintf(buffer + pos,
tomoyo_buffer_len - 1 - pos,
" dev_major=%u dev_minor=%u",
MAJOR(dev), MINOR(dev));
}
pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
" }");
}
no_obj_info:
if (pos < tomoyo_buffer_len - 1)
return buffer;
kfree(buffer);
return NULL;
}
/**
* tomoyo_init_log - Allocate buffer for audit logs.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns pointer to allocated memory.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf = NULL;
char *bprm_info = NULL;
const char *header = NULL;
char *realpath = NULL;
const char *symlink = NULL;
int pos;
const char *domainname = r->domain->domainname->name;
header = tomoyo_print_header(r);
if (!header)
return NULL;
/* +10 is for '\n' etc. and '\0'. */
len += strlen(domainname) + strlen(header) + 10;
if (r->ee) {
struct file *file = r->ee->bprm->file;
realpath = tomoyo_realpath_from_path(&file->f_path);
bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
if (!realpath || !bprm_info)
goto out;
/* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
len += strlen(realpath) + 80 + strlen(bprm_info);
} else if (r->obj && r->obj->symlink_target) {
symlink = r->obj->symlink_target->name;
/* +18 is for " symlink.target=\"%s\"" */
len += 18 + strlen(symlink);
}
len = tomoyo_round2(len);
buf = kzalloc(len, GFP_NOFS);
if (!buf)
goto out;
len--;
pos = snprintf(buf, len, "%s", header);
if (realpath) {
struct linux_binprm *bprm = r->ee->bprm;
pos += snprintf(buf + pos, len - pos,
" exec={ realpath=\"%s\" argc=%d envc=%d %s }",
realpath, bprm->argc, bprm->envc, bprm_info);
} else if (symlink)
pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
symlink);
pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
vsnprintf(buf + pos, len - pos, fmt, args);
out:
kfree(realpath);
kfree(bprm_info);
kfree(header);
return buf;
}
/* Wait queue for /sys/kernel/security/tomoyo/audit. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
/* Structure for audit log. */
struct tomoyo_log {
struct list_head list;
char *log;
int size;
};
/* The list for "struct tomoyo_log". */
static LIST_HEAD(tomoyo_log);
/* Lock for "struct list_head tomoyo_log". */
static DEFINE_SPINLOCK(tomoyo_log_lock);
/* Length of "struct list_head tomoyo_log". */
static unsigned int tomoyo_log_count;
/**
* tomoyo_get_audit - Get audit mode.
*
* @ns: Pointer to "struct tomoyo_policy_namespace".
* @profile: Profile number.
* @index: Index number of functionality.
* @matched_acl: Pointer to "struct tomoyo_acl_info".
* @is_granted: True if granted log, false otherwise.
*
* Returns true if this request should be audited, false otherwise.
*/
static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
const u8 profile, const u8 index,
const struct tomoyo_acl_info *matched_acl,
const bool is_granted)
{
u8 mode;
const u8 category = tomoyo_index2category[index] +
TOMOYO_MAX_MAC_INDEX;
struct tomoyo_profile *p;
if (!tomoyo_policy_loaded)
return false;
p = tomoyo_profile(ns, profile);
if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
return false;
if (is_granted && matched_acl && matched_acl->cond &&
matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
mode = p->config[index];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->config[category];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->default_config;
if (is_granted)
return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
}
/**
* tomoyo_write_log2 - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns nothing.
*/
void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf;
struct tomoyo_log *entry;
bool quota_exceeded = false;
if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
r->matched_acl, r->granted))
goto out;
buf = tomoyo_init_log(r, len, fmt, args);
if (!buf)
goto out;
entry = kzalloc(sizeof(*entry), GFP_NOFS);
if (!entry) {
kfree(buf);
goto out;
}
entry->log = buf;
len = tomoyo_round2(strlen(buf) + 1);
/*
* The entry->size is used for memory quota checks.
* Don't go beyond strlen(entry->log).
*/
entry->size = len + tomoyo_round2(sizeof(*entry));
spin_lock(&tomoyo_log_lock);
if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
quota_exceeded = true;
} else {
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
list_add_tail(&entry->list, &tomoyo_log);
tomoyo_log_count++;
}
spin_unlock(&tomoyo_log_lock);
if (quota_exceeded) {
kfree(buf);
kfree(entry);
goto out;
}
wake_up(&tomoyo_log_wait);
out:
return;
}
/**
* tomoyo_write_log - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @fmt: The printf()'s format string, followed by parameters.
*
* Returns nothing.
*/
void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
{
va_list args;
int len;
va_start(args, fmt);
len = vsnprintf((char *) &len, 1, fmt, args) + 1;
va_end(args);
va_start(args, fmt);
tomoyo_write_log2(r, len, fmt, args);
va_end(args);
}
/**
* tomoyo_read_log - Read an audit log.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns nothing.
*/
void tomoyo_read_log(struct tomoyo_io_buffer *head)
{
struct tomoyo_log *ptr = NULL;
if (head->r.w_pos)
return;
kfree(head->read_buf);
head->read_buf = NULL;
spin_lock(&tomoyo_log_lock);
if (!list_empty(&tomoyo_log)) {
ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
list_del(&ptr->list);
tomoyo_log_count--;
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
}
spin_unlock(&tomoyo_log_lock);
if (ptr) {
head->read_buf = ptr->log;
head->r.w[head->r.w_pos++] = head->read_buf;
kfree(ptr);
}
}
/**
* tomoyo_poll_log - Wait for an audit log.
*
* @file: Pointer to "struct file".
* @wait: Pointer to "poll_table". Maybe NULL.
*
* Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log.
*/
__poll_t tomoyo_poll_log(struct file *file, poll_table *wait)
{
if (tomoyo_log_count)
return EPOLLIN | EPOLLRDNORM;
poll_wait(file, &tomoyo_log_wait, wait);
if (tomoyo_log_count)
return EPOLLIN | EPOLLRDNORM;
return 0;
}
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