From 731d37aa70c7b9de3be6bf2c8287366223bf5ce5 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Sat, 10 Sep 2011 15:25:58 +0900 Subject: TOMOYO: Allow domain transition without execve(). To be able to split permissions for Apache's CGI programs which are executed without execve(), add special domain transition which is performed by writing a TOMOYO's domainname to /sys/kernel/security/tomoyo/self_domain interface. This is an API for TOMOYO-aware userland applications. However, since I expect TOMOYO and other LSM modules to run in parallel, this patch does not use /proc/self/attr/ interface in order to avoid conflicts with other LSM modules when it became possible to run multiple LSM modules in parallel. Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- security/tomoyo/common.c | 75 ++++++++++++++++-------- security/tomoyo/common.h | 16 +++++- security/tomoyo/securityfs_if.c | 122 +++++++++++++++++++++++++++++++++++++++- security/tomoyo/util.c | 25 ++++++++ 4 files changed, 210 insertions(+), 28 deletions(-) (limited to 'security/tomoyo') diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index 2704c38..1fd0fc1 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -1011,6 +1011,48 @@ static bool tomoyo_select_domain(struct tomoyo_io_buffer *head, } /** + * tomoyo_same_task_acl - Check for duplicated "struct tomoyo_task_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_task_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_task_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_task_acl *p2 = container_of(b, typeof(*p2), head); + return p1->domainname == p2->domainname; +} + +/** + * tomoyo_write_task - Update task related list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_task(struct tomoyo_acl_param *param) +{ + int error = -EINVAL; + if (tomoyo_str_starts(¶m->data, "manual_domain_transition ")) { + struct tomoyo_task_acl e = { + .head.type = TOMOYO_TYPE_MANUAL_TASK_ACL, + .domainname = tomoyo_get_domainname(param), + }; + if (e.domainname) + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_task_acl, + NULL); + tomoyo_put_name(e.domainname); + } + return error; +} + +/** * tomoyo_delete_domain - Delete a domain. * * @domainname: The name of domain. @@ -1068,11 +1110,12 @@ static int tomoyo_write_domain2(struct tomoyo_policy_namespace *ns, static const struct { const char *keyword; int (*write) (struct tomoyo_acl_param *); - } tomoyo_callback[4] = { + } tomoyo_callback[5] = { { "file ", tomoyo_write_file }, { "network inet ", tomoyo_write_inet_network }, { "network unix ", tomoyo_write_unix_network }, { "misc ", tomoyo_write_misc }, + { "task ", tomoyo_write_task }, }; u8 i; @@ -1343,6 +1386,12 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head, if (first) return true; tomoyo_print_name_union(head, &ptr->name); + } else if (acl_type == TOMOYO_TYPE_MANUAL_TASK_ACL) { + struct tomoyo_task_acl *ptr = + container_of(acl, typeof(*ptr), head); + tomoyo_set_group(head, "task "); + tomoyo_set_string(head, "manual_domain_transition "); + tomoyo_set_string(head, ptr->domainname->name); } else if (head->r.print_transition_related_only) { return true; } else if (acl_type == TOMOYO_TYPE_PATH2_ACL) { @@ -2178,26 +2227,6 @@ static void tomoyo_read_version(struct tomoyo_io_buffer *head) } } -/** - * tomoyo_read_self_domain - Get the current process's domainname. - * - * @head: Pointer to "struct tomoyo_io_buffer". - * - * Returns the current process's domainname. - */ -static void tomoyo_read_self_domain(struct tomoyo_io_buffer *head) -{ - if (!head->r.eof) { - /* - * tomoyo_domain()->domainname != NULL - * because every process belongs to a domain and - * the domain's name cannot be NULL. - */ - tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name); - head->r.eof = true; - } -} - /* String table for /sys/kernel/security/tomoyo/stat interface. */ static const char * const tomoyo_policy_headers[TOMOYO_MAX_POLICY_STAT] = { [TOMOYO_STAT_POLICY_UPDATES] = "update:", @@ -2328,10 +2357,6 @@ int tomoyo_open_control(const u8 type, struct file *file) head->poll = tomoyo_poll_log; head->read = tomoyo_read_log; break; - case TOMOYO_SELFDOMAIN: - /* /sys/kernel/security/tomoyo/self_domain */ - head->read = tomoyo_read_self_domain; - break; case TOMOYO_PROCESS_STATUS: /* /sys/kernel/security/tomoyo/.process_status */ head->write = tomoyo_write_pid; diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h index 435b3d8..af82683 100644 --- a/security/tomoyo/common.h +++ b/security/tomoyo/common.h @@ -227,6 +227,7 @@ enum tomoyo_acl_entry_type_index { TOMOYO_TYPE_INET_ACL, TOMOYO_TYPE_UNIX_ACL, TOMOYO_TYPE_ENV_ACL, + TOMOYO_TYPE_MANUAL_TASK_ACL, }; /* Index numbers for access controls with one pathname. */ @@ -295,7 +296,6 @@ enum tomoyo_securityfs_interface_index { TOMOYO_EXCEPTIONPOLICY, TOMOYO_PROCESS_STATUS, TOMOYO_STAT, - TOMOYO_SELFDOMAIN, TOMOYO_AUDIT, TOMOYO_VERSION, TOMOYO_PROFILE, @@ -480,6 +480,9 @@ struct tomoyo_request_info { unsigned long flags; int need_dev; } mount; + struct { + const struct tomoyo_path_info *domainname; + } task; } param; struct tomoyo_acl_info *matched_acl; u8 param_type; @@ -680,6 +683,15 @@ struct tomoyo_domain_info { }; /* + * Structure for "task manual_domain_transition" directive. + */ +struct tomoyo_task_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_MANUAL_TASK_ACL */ + /* Pointer to domainname. */ + const struct tomoyo_path_info *domainname; +}; + +/* * Structure for "file execute", "file read", "file write", "file append", * "file unlink", "file getattr", "file rmdir", "file truncate", * "file symlink", "file chroot" and "file unmount" directive. @@ -935,6 +947,8 @@ const char *tomoyo_get_exe(void); const char *tomoyo_yesno(const unsigned int value); const struct tomoyo_path_info *tomoyo_compare_name_union (const struct tomoyo_path_info *name, const struct tomoyo_name_union *ptr); +const struct tomoyo_path_info *tomoyo_get_domainname +(struct tomoyo_acl_param *param); const struct tomoyo_path_info *tomoyo_get_name(const char *name); const struct tomoyo_path_info *tomoyo_path_matches_group (const struct tomoyo_path_info *pathname, const struct tomoyo_group *group); diff --git a/security/tomoyo/securityfs_if.c b/security/tomoyo/securityfs_if.c index a49c3bf..d08296a 100644 --- a/security/tomoyo/securityfs_if.c +++ b/security/tomoyo/securityfs_if.c @@ -8,6 +8,124 @@ #include "common.h" /** + * tomoyo_check_task_acl - Check permission for task operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_task_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_task_acl *acl = container_of(ptr, typeof(*acl), + head); + return !tomoyo_pathcmp(r->param.task.domainname, acl->domainname); +} + +/** + * tomoyo_write_self - write() for /sys/kernel/security/tomoyo/self_domain interface. + * + * @file: Pointer to "struct file". + * @buf: Domainname to transit to. + * @count: Size of @buf. + * @ppos: Unused. + * + * Returns @count on success, negative value otherwise. + * + * If domain transition was permitted but the domain transition failed, this + * function returns error rather than terminating current thread with SIGKILL. + */ +static ssize_t tomoyo_write_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + int error; + if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10) + return -ENOMEM; + data = kzalloc(count + 1, GFP_NOFS); + if (!data) + return -ENOMEM; + if (copy_from_user(data, buf, count)) { + error = -EFAULT; + goto out; + } + tomoyo_normalize_line(data); + if (tomoyo_correct_domain(data)) { + const int idx = tomoyo_read_lock(); + struct tomoyo_path_info name; + struct tomoyo_request_info r; + name.name = data; + tomoyo_fill_path_info(&name); + /* Check "task manual_domain_transition" permission. */ + tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE); + r.param_type = TOMOYO_TYPE_MANUAL_TASK_ACL; + r.param.task.domainname = &name; + tomoyo_check_acl(&r, tomoyo_check_task_acl); + if (!r.granted) + error = -EPERM; + else { + struct tomoyo_domain_info *new_domain = + tomoyo_assign_domain(data, true); + if (!new_domain) { + error = -ENOENT; + } else { + struct cred *cred = prepare_creds(); + if (!cred) { + error = -ENOMEM; + } else { + struct tomoyo_domain_info *old_domain = + cred->security; + cred->security = new_domain; + atomic_inc(&new_domain->users); + atomic_dec(&old_domain->users); + commit_creds(cred); + error = 0; + } + } + } + tomoyo_read_unlock(idx); + } else + error = -EINVAL; +out: + kfree(data); + return error ? error : count; +} + +/** + * tomoyo_read_self - read() for /sys/kernel/security/tomoyo/self_domain interface. + * + * @file: Pointer to "struct file". + * @buf: Domainname which current thread belongs to. + * @count: Size of @buf. + * @ppos: Bytes read by now. + * + * Returns read size on success, negative value otherwise. + */ +static ssize_t tomoyo_read_self(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + const char *domain = tomoyo_domain()->domainname->name; + loff_t len = strlen(domain); + loff_t pos = *ppos; + if (pos >= len || !count) + return 0; + len -= pos; + if (count < len) + len = count; + if (copy_to_user(buf, domain + pos, len)) + return -EFAULT; + *ppos += len; + return len; +} + +/* Operations for /sys/kernel/security/tomoyo/self_domain interface. */ +static const struct file_operations tomoyo_self_operations = { + .write = tomoyo_write_self, + .read = tomoyo_read_self, +}; + +/** * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface. * * @inode: Pointer to "struct inode". @@ -135,8 +253,6 @@ static int __init tomoyo_initerface_init(void) TOMOYO_EXCEPTIONPOLICY); tomoyo_create_entry("audit", 0400, tomoyo_dir, TOMOYO_AUDIT); - tomoyo_create_entry("self_domain", 0400, tomoyo_dir, - TOMOYO_SELFDOMAIN); tomoyo_create_entry(".process_status", 0600, tomoyo_dir, TOMOYO_PROCESS_STATUS); tomoyo_create_entry("stat", 0644, tomoyo_dir, @@ -147,6 +263,8 @@ static int __init tomoyo_initerface_init(void) TOMOYO_MANAGER); tomoyo_create_entry("version", 0400, tomoyo_dir, TOMOYO_VERSION); + securityfs_create_file("self_domain", 0666, tomoyo_dir, NULL, + &tomoyo_self_operations); return 0; } diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c index a1c3d9c..50e9b4c 100644 --- a/security/tomoyo/util.c +++ b/security/tomoyo/util.c @@ -159,6 +159,31 @@ char *tomoyo_read_token(struct tomoyo_acl_param *param) } /** + * tomoyo_get_domainname - Read a domainname from a line. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns a domainname on success, NULL otherwise. + */ +const struct tomoyo_path_info *tomoyo_get_domainname +(struct tomoyo_acl_param *param) +{ + char *start = param->data; + char *pos = start; + while (*pos) { + if (*pos++ != ' ' || *pos++ == '/') + continue; + pos -= 2; + *pos++ = '\0'; + break; + } + param->data = pos; + if (tomoyo_correct_domain(start)) + return tomoyo_get_name(start); + return NULL; +} + +/** * tomoyo_parse_ulong - Parse an "unsigned long" value. * * @result: Pointer to "unsigned long". -- cgit v1.1