TOMOYO: Remove alias keyword.

Some programs behave differently depending on argv[0] passed to execve().
TOMOYO has "alias" keyword in order to allow administrators to define different
domains if requested pathname passed to execve() is a symlink. But "alias"
keyword is incomplete because this keyword assumes that requested pathname and
argv[0] are identical. Thus, remove "alias" keyword (by this patch) and add
syntax for checking argv[0] (by future patches).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 3 insertions, 97 deletions

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 038071a8a3d3..273e670acf0c 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -467,72 +467,6 @@ int tomoyo_write_aggregator_policy(char *data, const bool is_delete)
         return tomoyo_update_aggregator_entry(data, cp, is_delete);
 }
 
-static bool tomoyo_same_alias_entry(const struct tomoyo_acl_head *a,
-                                    const struct tomoyo_acl_head *b)
-{
-        const struct tomoyo_alias_entry *p1 = container_of(a, typeof(*p1),
-                                                           head);
-        const struct tomoyo_alias_entry *p2 = container_of(b, typeof(*p2),
-                                                           head);
-        return p1->original_name == p2->original_name &&
-                p1->aliased_name == p2->aliased_name;
-}
-
-/**
- * tomoyo_update_alias_entry - Update "struct tomoyo_alias_entry" list.
- *
- * @original_name: The original program's real name.
- * @aliased_name:  The symbolic program's symbolic link's name.
- * @is_delete:     True if it is a delete request.
- *
- * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-static int tomoyo_update_alias_entry(const char *original_name,
-                                     const char *aliased_name,
-                                     const bool is_delete)
-{
-        struct tomoyo_alias_entry e = { };
-        int error = is_delete ? -ENOENT : -ENOMEM;
-
-        if (!tomoyo_correct_path(original_name) ||
-            !tomoyo_correct_path(aliased_name))
-                return -EINVAL;
-        e.original_name = tomoyo_get_name(original_name);
-        e.aliased_name = tomoyo_get_name(aliased_name);
-        if (!e.original_name || !e.aliased_name ||
-            e.original_name->is_patterned || e.aliased_name->is_patterned)
-                goto out; /* No patterns allowed. */
-        error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
-                                     &tomoyo_policy_list[TOMOYO_ID_ALIAS],
-                                     tomoyo_same_alias_entry);
- out:
-        tomoyo_put_name(e.original_name);
-        tomoyo_put_name(e.aliased_name);
-        return error;
-}
-
-/**
- * tomoyo_write_alias_policy - Write "struct tomoyo_alias_entry" list.
- *
- * @data:      String to parse.
- * @is_delete: True if it is a delete request.
- *
- * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-int tomoyo_write_alias_policy(char *data, const bool is_delete)
-{
-        char *cp = strchr(data, ' ');
-
-        if (!cp)
-                return -EINVAL;
-        *cp++ = '\0';
-        return tomoyo_update_alias_entry(data, cp, is_delete);
-}
-
 /**
  * tomoyo_find_or_assign_new_domain - Create a domain.
  *
@@ -606,7 +540,6 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
         int retval = -ENOMEM;
         bool need_kfree = false;
         struct tomoyo_path_info rn = { }; /* real name */
-        struct tomoyo_path_info sn = { }; /* symlink name */
         struct tomoyo_path_info ln; /* last name */
 
         ln.name = tomoyo_get_last_name(old_domain);
@@ -621,39 +554,14 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
                 kfree(rn.name);
                 need_kfree = false;
         }
-        /* Get tomoyo_realpath of program. */
+        /* Get symlink's pathname of program. */
         retval = -ENOENT;
-        rn.name = tomoyo_realpath(original_name);
+        rn.name = tomoyo_realpath_nofollow(original_name);
         if (!rn.name)
                 goto out;
         tomoyo_fill_path_info(&rn);
         need_kfree = true;
 
-        /* Get tomoyo_realpath of symbolic link. */
-        sn.name = tomoyo_realpath_nofollow(original_name);
-        if (!sn.name)
-                goto out;
-        tomoyo_fill_path_info(&sn);
-
-        /* Check 'alias' directive. */
-        if (tomoyo_pathcmp(&rn, &sn)) {
-                struct tomoyo_alias_entry *ptr;
-                /* Is this program allowed to be called via symbolic links? */
-                list_for_each_entry_rcu(ptr,
-                                        &tomoyo_policy_list[TOMOYO_ID_ALIAS],
-                                        head.list) {
-                        if (ptr->head.is_deleted ||
-                            tomoyo_pathcmp(&rn, ptr->original_name) ||
-                            tomoyo_pathcmp(&sn, ptr->aliased_name))
-                                continue;
-                        kfree(rn.name);
-                        need_kfree = false;
-                        /* This is OK because it is read only. */
-                        rn = *ptr->aliased_name;
-                        break;
-                }
-        }
-
         /* Check 'aggregator' directive. */
         {
                 struct tomoyo_aggregator_entry *ptr;
@@ -663,8 +571,7 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
                             !tomoyo_path_matches_pattern(&rn,
                                                          ptr->original_name))
                                 continue;
-                        if (need_kfree)
-                                kfree(rn.name);
+                        kfree(rn.name);
                         need_kfree = false;
                         /* This is OK because it is read only. */
                         rn = *ptr->aggregated_name;
@@ -729,7 +636,6 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
         bprm->cred->security = domain;
         if (need_kfree)
                 kfree(rn.name);
-        kfree(sn.name);
         kfree(tmp);
         return retval;
 }