diff options
Diffstat (limited to 'security/tomoyo/audit.c')
| -rw-r--r-- | security/tomoyo/audit.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c new file mode 100644 index 000000000000..5dbb1f7617c0 --- /dev/null +++ b/security/tomoyo/audit.c @@ -0,0 +1,456 @@ +/* + * 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 mode_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; + { + struct timeval tv; + do_gettimeofday(&tv); + tomoyo_convert_time(tv.tv_sec, &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], tomoyo_yesno(r->granted), gpid, + tomoyo_sys_getpid(), tomoyo_sys_getppid(), + current_uid(), current_gid(), current_euid(), + current_egid(), current_suid(), current_sgid(), + current_fsuid(), 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; + mode_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, + stat->uid, 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, + stat->uid, 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 "stuct 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. + * @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 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; + 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->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". + * + * Returns POLLIN | POLLRDNORM when ready to read an audit log. + */ +int tomoyo_poll_log(struct file *file, poll_table *wait) +{ + if (tomoyo_log_count) + return POLLIN | POLLRDNORM; + poll_wait(file, &tomoyo_log_wait, wait); + if (tomoyo_log_count) + return POLLIN | POLLRDNORM; + return 0; +} |