TOMOYO: Add refcounter on string data.

Add refcounter to "struct tomoyo_name_entry" and replace tomoyo_save_name()
with tomoyo_get_name()/tomoyo_put_name() pair so that we can kfree() when
garbage collector is added.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

5 files changed, 77 insertions, 40 deletions

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index a53ee059da48..0c7ea51e7a45 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -12,8 +12,8 @@
 #include <linux/uaccess.h>
 #include <linux/security.h>
 #include <linux/hardirq.h>
-#include "realpath.h"
 #include "common.h"
+#include "realpath.h"
 #include "tomoyo.h"
 
 /* Lock for protecting policy. */
@@ -943,7 +943,9 @@ static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
                 return -EINVAL;
         *cp = '\0';
         if (!strcmp(data, "COMMENT")) {
-                profile->comment = tomoyo_save_name(cp + 1);
+                const struct tomoyo_path_info *old_comment = profile->comment;
+                profile->comment = tomoyo_get_name(cp + 1);
+                tomoyo_put_name(old_comment);
                 return 0;
         }
         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
@@ -1117,7 +1119,7 @@ static int tomoyo_update_manager_entry(const char *manager,
                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
                         return -EINVAL;
         }
-        saved_manager = tomoyo_save_name(manager);
+        saved_manager = tomoyo_get_name(manager);
         if (!saved_manager)
                 return -ENOMEM;
         if (!is_delete)
@@ -1132,12 +1134,14 @@ static int tomoyo_update_manager_entry(const char *manager,
         }
         if (!is_delete && error && tomoyo_memory_ok(entry)) {
                 entry->manager = saved_manager;
+                saved_manager = NULL;
                 entry->is_domain = is_domain;
                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
                 entry = NULL;
                 error = 0;
         }
         mutex_unlock(&tomoyo_policy_lock);
+        tomoyo_put_name(saved_manager);
         kfree(entry);
         return error;
 }
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 229de1e71a38..0b8262567809 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -203,7 +203,7 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
 {
         struct tomoyo_domain_initializer_entry *entry = NULL;
         struct tomoyo_domain_initializer_entry *ptr;
-        const struct tomoyo_path_info *saved_program;
+        const struct tomoyo_path_info *saved_program = NULL;
         const struct tomoyo_path_info *saved_domainname = NULL;
         int error = is_delete ? -ENOENT : -ENOMEM;
         bool is_last_name = false;
@@ -216,11 +216,11 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
                         is_last_name = true;
                 else if (!tomoyo_is_correct_domain(domainname, __func__))
                         return -EINVAL;
-                saved_domainname = tomoyo_save_name(domainname);
+                saved_domainname = tomoyo_get_name(domainname);
                 if (!saved_domainname)
                         goto out;
         }
-        saved_program = tomoyo_save_name(program);
+        saved_program = tomoyo_get_name(program);
         if (!saved_program)
                 goto out;
         if (!is_delete)
@@ -237,7 +237,9 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
         }
         if (!is_delete && error && tomoyo_memory_ok(entry)) {
                 entry->domainname = saved_domainname;
+                saved_domainname = NULL;
                 entry->program = saved_program;
+                saved_program = NULL;
                 entry->is_not = is_not;
                 entry->is_last_name = is_last_name;
                 list_add_tail_rcu(&entry->list,
@@ -247,6 +249,8 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
         }
         mutex_unlock(&tomoyo_policy_lock);
  out:
+        tomoyo_put_name(saved_domainname);
+        tomoyo_put_name(saved_program);
         kfree(entry);
         return error;
 }
@@ -419,7 +423,7 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
 {
         struct tomoyo_domain_keeper_entry *entry = NULL;
         struct tomoyo_domain_keeper_entry *ptr;
-        const struct tomoyo_path_info *saved_domainname;
+        const struct tomoyo_path_info *saved_domainname = NULL;
         const struct tomoyo_path_info *saved_program = NULL;
         int error = is_delete ? -ENOENT : -ENOMEM;
         bool is_last_name = false;
@@ -432,11 +436,11 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
         if (program) {
                 if (!tomoyo_is_correct_path(program, 1, -1, -1, __func__))
                         return -EINVAL;
-                saved_program = tomoyo_save_name(program);
+                saved_program = tomoyo_get_name(program);
                 if (!saved_program)
                         goto out;
         }
-        saved_domainname = tomoyo_save_name(domainname);
+        saved_domainname = tomoyo_get_name(domainname);
         if (!saved_domainname)
                 goto out;
         if (!is_delete)
@@ -453,7 +457,9 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
         }
         if (!is_delete && error && tomoyo_memory_ok(entry)) {
                 entry->domainname = saved_domainname;
+                saved_domainname = NULL;
                 entry->program = saved_program;
+                saved_program = NULL;
                 entry->is_not = is_not;
                 entry->is_last_name = is_last_name;
                 list_add_tail_rcu(&entry->list, &tomoyo_domain_keeper_list);
@@ -462,6 +468,8 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
         }
         mutex_unlock(&tomoyo_policy_lock);
  out:
+        tomoyo_put_name(saved_domainname);
+        tomoyo_put_name(saved_program);
         kfree(entry);
         return error;
 }
@@ -623,8 +631,8 @@ static int tomoyo_update_alias_entry(const char *original_name,
         if (!tomoyo_is_correct_path(original_name, 1, -1, -1, __func__) ||
             !tomoyo_is_correct_path(aliased_name, 1, -1, -1, __func__))
                 return -EINVAL; /* No patterns allowed. */
-        saved_original_name = tomoyo_save_name(original_name);
-        saved_aliased_name = tomoyo_save_name(aliased_name);
+        saved_original_name = tomoyo_get_name(original_name);
+        saved_aliased_name = tomoyo_get_name(aliased_name);
         if (!saved_original_name || !saved_aliased_name)
                 goto out;