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 <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
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 @@
}
/**
+ * 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 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 @@
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 @@
}
}
-/**
- * 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 @@
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 @@
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 @@
TOMOYO_EXCEPTIONPOLICY,
TOMOYO_PROCESS_STATUS,
TOMOYO_STAT,
- TOMOYO_SELFDOMAIN,
TOMOYO_AUDIT,
TOMOYO_VERSION,
TOMOYO_PROFILE,
@@ -480,6 +480,9 @@
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 @@
};
/*
+ * 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_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 @@
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 @@
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 @@
}
/**
+ * 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".