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