TOMOYO: Use stack memory for pending entry.

Use stack memory for pending entry to reduce kmalloc() which will be kfree()d.

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

5 files changed, 190 insertions, 192 deletions

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 8f34036..62e089c 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -1071,46 +1071,42 @@ LIST_HEAD(tomoyo_policy_manager_list);
 static int tomoyo_update_manager_entry(const char *manager,
 				       const bool is_delete)
 {
-	struct tomoyo_policy_manager_entry *entry = NULL;
 	struct tomoyo_policy_manager_entry *ptr;
-	const struct tomoyo_path_info *saved_manager;
+	struct tomoyo_policy_manager_entry e = { };
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	bool is_domain = false;
 
 	if (tomoyo_is_domain_def(manager)) {
 		if (!tomoyo_is_correct_domain(manager))
 			return -EINVAL;
-		is_domain = true;
+		e.is_domain = true;
 	} else {
 		if (!tomoyo_is_correct_path(manager, 1, -1, -1))
 			return -EINVAL;
 	}
-	saved_manager = tomoyo_get_name(manager);
-	if (!saved_manager)
+	e.manager = tomoyo_get_name(manager);
+	if (!e.manager)
 		return -ENOMEM;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
-		if (ptr->manager != saved_manager)
+		if (ptr->manager != e.manager)
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	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;
+	if (!is_delete && error) {
+		struct tomoyo_policy_manager_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_policy_manager_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_manager);
-	kfree(entry);
+	tomoyo_put_name(e.manager);
 	return error;
 }
 
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index 52c9502..c95f486 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -616,6 +616,7 @@ char *tomoyo_realpath_from_path(struct path *path);
 
 /* Check memory quota. */
 bool tomoyo_memory_ok(void *ptr);
+void *tomoyo_commit_ok(void *data, const unsigned int size);
 
 /*
  * Keep the given name on the RAM.
@@ -735,6 +736,31 @@ static inline struct tomoyo_domain_info *tomoyo_real_domain(struct task_struct
 	return task_cred_xxx(task, security);
 }
 
+static inline bool tomoyo_is_same_domain_initializer_entry
+(const struct tomoyo_domain_initializer_entry *p1,
+ const struct tomoyo_domain_initializer_entry *p2)
+{
+	return p1->is_not == p2->is_not && p1->is_last_name == p2->is_last_name
+		&& p1->domainname == p2->domainname
+		&& p1->program == p2->program;
+}
+
+static inline bool tomoyo_is_same_domain_keeper_entry
+(const struct tomoyo_domain_keeper_entry *p1,
+ const struct tomoyo_domain_keeper_entry *p2)
+{
+	return p1->is_not == p2->is_not && p1->is_last_name == p2->is_last_name
+		&& p1->domainname == p2->domainname
+		&& p1->program == p2->program;
+}
+
+static inline bool tomoyo_is_same_alias_entry
+(const struct tomoyo_alias_entry *p1, const struct tomoyo_alias_entry *p2)
+{
+	return p1->original_name == p2->original_name &&
+		p1->aliased_name == p2->aliased_name;
+}
+
 /**
  * list_for_each_cookie - iterate over a list with cookie.
  * @pos:        the &struct list_head to use as a loop cursor.
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index a1723bb..cd8ba44 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -130,58 +130,47 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
 						  const bool is_not,
 						  const bool is_delete)
 {
-	struct tomoyo_domain_initializer_entry *entry = NULL;
 	struct tomoyo_domain_initializer_entry *ptr;
-	const struct tomoyo_path_info *saved_program = NULL;
-	const struct tomoyo_path_info *saved_domainname = NULL;
+	struct tomoyo_domain_initializer_entry e = { .is_not = is_not };
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	bool is_last_name = false;
 
 	if (!tomoyo_is_correct_path(program, 1, -1, -1))
 		return -EINVAL; /* No patterns allowed. */
 	if (domainname) {
 		if (!tomoyo_is_domain_def(domainname) &&
 		    tomoyo_is_correct_path(domainname, 1, -1, -1))
-			is_last_name = true;
+			e.is_last_name = true;
 		else if (!tomoyo_is_correct_domain(domainname))
 			return -EINVAL;
-		saved_domainname = tomoyo_get_name(domainname);
-		if (!saved_domainname)
+		e.domainname = tomoyo_get_name(domainname);
+		if (!e.domainname)
 			goto out;
 	}
-	saved_program = tomoyo_get_name(program);
-	if (!saved_program)
+	e.program = tomoyo_get_name(program);
+	if (!e.program)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) {
-		if (ptr->is_not != is_not ||
-		    ptr->domainname != saved_domainname ||
-		    ptr->program != saved_program)
+		if (!tomoyo_is_same_domain_initializer_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	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_initializer_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_domain_initializer_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_domain_initializer_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_domainname);
-	tomoyo_put_name(saved_program);
-	kfree(entry);
+	tomoyo_put_name(e.domainname);
+	tomoyo_put_name(e.program);
 	return error;
 }
 
@@ -351,57 +340,47 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
 					     const bool is_not,
 					     const bool is_delete)
 {
-	struct tomoyo_domain_keeper_entry *entry = NULL;
 	struct tomoyo_domain_keeper_entry *ptr;
-	const struct tomoyo_path_info *saved_domainname = NULL;
-	const struct tomoyo_path_info *saved_program = NULL;
+	struct tomoyo_domain_keeper_entry e = { .is_not = is_not };
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	bool is_last_name = false;
 
 	if (!tomoyo_is_domain_def(domainname) &&
 	    tomoyo_is_correct_path(domainname, 1, -1, -1))
-		is_last_name = true;
+		e.is_last_name = true;
 	else if (!tomoyo_is_correct_domain(domainname))
 		return -EINVAL;
 	if (program) {
 		if (!tomoyo_is_correct_path(program, 1, -1, -1))
 			return -EINVAL;
-		saved_program = tomoyo_get_name(program);
-		if (!saved_program)
+		e.program = tomoyo_get_name(program);
+		if (!e.program)
 			goto out;
 	}
-	saved_domainname = tomoyo_get_name(domainname);
-	if (!saved_domainname)
+	e.domainname = tomoyo_get_name(domainname);
+	if (!e.domainname)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) {
-		if (ptr->is_not != is_not ||
-		    ptr->domainname != saved_domainname ||
-		    ptr->program != saved_program)
+		if (!tomoyo_is_same_domain_keeper_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	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);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_domain_keeper_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_domain_keeper_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_domainname);
-	tomoyo_put_name(saved_program);
-	kfree(entry);
+	tomoyo_put_name(e.domainname);
+	tomoyo_put_name(e.program);
 	return error;
 }
 
@@ -553,45 +532,38 @@ static int tomoyo_update_alias_entry(const char *original_name,
 				     const char *aliased_name,
 				     const bool is_delete)
 {
-	struct tomoyo_alias_entry *entry = NULL;
 	struct tomoyo_alias_entry *ptr;
-	const struct tomoyo_path_info *saved_original_name;
-	const struct tomoyo_path_info *saved_aliased_name;
+	struct tomoyo_alias_entry e = { };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 
 	if (!tomoyo_is_correct_path(original_name, 1, -1, -1) ||
 	    !tomoyo_is_correct_path(aliased_name, 1, -1, -1))
 		return -EINVAL; /* No patterns allowed. */
-	saved_original_name = tomoyo_get_name(original_name);
-	saved_aliased_name = tomoyo_get_name(aliased_name);
-	if (!saved_original_name || !saved_aliased_name)
+	e.original_name = tomoyo_get_name(original_name);
+	e.aliased_name = tomoyo_get_name(aliased_name);
+	if (!e.original_name || !e.aliased_name)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
-		if (ptr->original_name != saved_original_name ||
-		    ptr->aliased_name != saved_aliased_name)
+		if (!tomoyo_is_same_alias_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->original_name = saved_original_name;
-		saved_original_name = NULL;
-		entry->aliased_name = saved_aliased_name;
-		saved_aliased_name = NULL;
-		list_add_tail_rcu(&entry->list, &tomoyo_alias_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_alias_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list, &tomoyo_alias_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_original_name);
-	tomoyo_put_name(saved_aliased_name);
-	kfree(entry);
+	tomoyo_put_name(e.original_name);
+	tomoyo_put_name(e.aliased_name);
 	return error;
 }
 
diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c
index 060bbf3..6651cac8 100644
--- a/security/tomoyo/file.c
+++ b/security/tomoyo/file.c
@@ -164,38 +164,36 @@ LIST_HEAD(tomoyo_globally_readable_list);
 static int tomoyo_update_globally_readable_entry(const char *filename,
 						 const bool is_delete)
 {
-	struct tomoyo_globally_readable_file_entry *entry = NULL;
 	struct tomoyo_globally_readable_file_entry *ptr;
-	const struct tomoyo_path_info *saved_filename;
+	struct tomoyo_globally_readable_file_entry e = { };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 
 	if (!tomoyo_is_correct_path(filename, 1, 0, -1))
 		return -EINVAL;
-	saved_filename = tomoyo_get_name(filename);
-	if (!saved_filename)
+	e.filename = tomoyo_get_name(filename);
+	if (!e.filename)
 		return -ENOMEM;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
-		if (ptr->filename != saved_filename)
+		if (ptr->filename != e.filename)
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->filename = saved_filename;
-		saved_filename = NULL;
-		list_add_tail_rcu(&entry->list, &tomoyo_globally_readable_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_globally_readable_file_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_globally_readable_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_filename);
-	kfree(entry);
+	tomoyo_put_name(e.filename);
 	return error;
 }
 
@@ -313,38 +311,34 @@ LIST_HEAD(tomoyo_pattern_list);
 static int tomoyo_update_file_pattern_entry(const char *pattern,
 					    const bool is_delete)
 {
-	struct tomoyo_pattern_entry *entry = NULL;
 	struct tomoyo_pattern_entry *ptr;
-	const struct tomoyo_path_info *saved_pattern;
+	struct tomoyo_pattern_entry e = { .pattern = tomoyo_get_name(pattern) };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 
-	saved_pattern = tomoyo_get_name(pattern);
-	if (!saved_pattern)
+	if (!e.pattern)
 		return error;
-	if (!saved_pattern->is_patterned)
+	if (!e.pattern->is_patterned)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
-		if (saved_pattern != ptr->pattern)
+		if (e.pattern != ptr->pattern)
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->pattern = saved_pattern;
-		saved_pattern = NULL;
-		list_add_tail_rcu(&entry->list, &tomoyo_pattern_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_pattern_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list, &tomoyo_pattern_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	kfree(entry);
-	tomoyo_put_name(saved_pattern);
+	tomoyo_put_name(e.pattern);
 	return error;
 }
 
@@ -467,38 +461,36 @@ LIST_HEAD(tomoyo_no_rewrite_list);
 static int tomoyo_update_no_rewrite_entry(const char *pattern,
 					  const bool is_delete)
 {
-	struct tomoyo_no_rewrite_entry *entry = NULL;
 	struct tomoyo_no_rewrite_entry *ptr;
-	const struct tomoyo_path_info *saved_pattern;
+	struct tomoyo_no_rewrite_entry e = { };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 
 	if (!tomoyo_is_correct_path(pattern, 0, 0, 0))
 		return -EINVAL;
-	saved_pattern = tomoyo_get_name(pattern);
-	if (!saved_pattern)
+	e.pattern = tomoyo_get_name(pattern);
+	if (!e.pattern)
 		return error;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
-		if (ptr->pattern != saved_pattern)
+		if (ptr->pattern != e.pattern)
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->pattern = saved_pattern;
-		saved_pattern = NULL;
-		list_add_tail_rcu(&entry->list, &tomoyo_no_rewrite_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_no_rewrite_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_no_rewrite_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_pattern);
-	kfree(entry);
+	tomoyo_put_name(e.pattern);
 	return error;
 }
 
@@ -810,23 +802,26 @@ static int tomoyo_update_path_acl(const u8 type, const char *filename,
 				  struct tomoyo_domain_info *const domain,
 				  const bool is_delete)
 {
-	static const u32 rw_mask =
+	static const u32 tomoyo_rw_mask =
 		(1 << TOMOYO_TYPE_READ) | (1 << TOMOYO_TYPE_WRITE);
-	const struct tomoyo_path_info *saved_filename;
+	const u32 perm = 1 << type;
 	struct tomoyo_acl_info *ptr;
-	struct tomoyo_path_acl *entry = NULL;
+	struct tomoyo_path_acl e = {
+		.head.type = TOMOYO_TYPE_PATH_ACL,
+		.perm_high = perm >> 16,
+		.perm = perm
+	};
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	const u32 perm = 1 << type;
 
+	if (type == TOMOYO_TYPE_READ_WRITE)
+		e.perm |= tomoyo_rw_mask;
 	if (!domain)
 		return -EINVAL;
 	if (!tomoyo_is_correct_path(filename, 0, 0, 0))
 		return -EINVAL;
-	saved_filename = tomoyo_get_name(filename);
-	if (!saved_filename)
+	e.filename = tomoyo_get_name(filename);
+	if (!e.filename)
 		return -ENOMEM;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
@@ -834,48 +829,42 @@ static int tomoyo_update_path_acl(const u8 type, const char *filename,
 			container_of(ptr, struct tomoyo_path_acl, head);
 		if (ptr->type != TOMOYO_TYPE_PATH_ACL)
 			continue;
-		if (acl->filename != saved_filename)
+		if (acl->filename != e.filename)
 			continue;
 		if (is_delete) {
 			if (perm <= 0xFFFF)
 				acl->perm &= ~perm;
 			else
 				acl->perm_high &= ~(perm >> 16);
-			if ((acl->perm & rw_mask) != rw_mask)
+			if ((acl->perm & tomoyo_rw_mask) != tomoyo_rw_mask)
 				acl->perm &= ~(1 << TOMOYO_TYPE_READ_WRITE);
 			else if (!(acl->perm & (1 << TOMOYO_TYPE_READ_WRITE)))
-				acl->perm &= ~rw_mask;
+				acl->perm &= ~tomoyo_rw_mask;
 		} else {
 			if (perm <= 0xFFFF)
 				acl->perm |= perm;
 			else
 				acl->perm_high |= (perm >> 16);
-			if ((acl->perm & rw_mask) == rw_mask)
+			if ((acl->perm & tomoyo_rw_mask) == tomoyo_rw_mask)
 				acl->perm |= 1 << TOMOYO_TYPE_READ_WRITE;
 			else if (acl->perm & (1 << TOMOYO_TYPE_READ_WRITE))
-				acl->perm |= rw_mask;
+				acl->perm |= tomoyo_rw_mask;
 		}
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->head.type = TOMOYO_TYPE_PATH_ACL;
-		if (perm <= 0xFFFF)
-			entry->perm = perm;
-		else
-			entry->perm_high = (perm >> 16);
-		if (perm == (1 << TOMOYO_TYPE_READ_WRITE))
-			entry->perm |= rw_mask;
-		entry->filename = saved_filename;
-		saved_filename = NULL;
-		list_add_tail_rcu(&entry->head.list, &domain->acl_info_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_path_acl *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->head.list,
+					  &domain->acl_info_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	kfree(entry);
-	tomoyo_put_name(saved_filename);
+	tomoyo_put_name(e.filename);
 	return error;
 }
 
@@ -897,24 +886,23 @@ static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
 				   struct tomoyo_domain_info *const domain,
 				   const bool is_delete)
 {
-	const struct tomoyo_path_info *saved_filename1;
-	const struct tomoyo_path_info *saved_filename2;
+	const u8 perm = 1 << type;
+	struct tomoyo_path2_acl e = {
+		.head.type = TOMOYO_TYPE_PATH2_ACL,
+		.perm = perm
+	};
 	struct tomoyo_acl_info *ptr;
-	struct tomoyo_path2_acl *entry = NULL;
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	const u8 perm = 1 << type;
 
 	if (!domain)
 		return -EINVAL;
 	if (!tomoyo_is_correct_path(filename1, 0, 0, 0) ||
 	    !tomoyo_is_correct_path(filename2, 0, 0, 0))
 		return -EINVAL;
-	saved_filename1 = tomoyo_get_name(filename1);
-	saved_filename2 = tomoyo_get_name(filename2);
-	if (!saved_filename1 || !saved_filename2)
+	e.filename1 = tomoyo_get_name(filename1);
+	e.filename2 = tomoyo_get_name(filename2);
+	if (!e.filename1 || !e.filename2)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
@@ -922,8 +910,8 @@ static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
 			container_of(ptr, struct tomoyo_path2_acl, head);
 		if (ptr->type != TOMOYO_TYPE_PATH2_ACL)
 			continue;
-		if (acl->filename1 != saved_filename1 ||
-		    acl->filename2 != saved_filename2)
+		if (acl->filename1 != e.filename1 ||
+		    acl->filename2 != e.filename2)
 			continue;
 		if (is_delete)
 			acl->perm &= ~perm;
@@ -932,22 +920,19 @@ static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->head.type = TOMOYO_TYPE_PATH2_ACL;
-		entry->perm = perm;
-		entry->filename1 = saved_filename1;
-		saved_filename1 = NULL;
-		entry->filename2 = saved_filename2;
-		saved_filename2 = NULL;
-		list_add_tail_rcu(&entry->head.list, &domain->acl_info_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_path2_acl *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->head.list,
+					  &domain->acl_info_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_filename1);
-	tomoyo_put_name(saved_filename2);
-	kfree(entry);
+	tomoyo_put_name(e.filename1);
+	tomoyo_put_name(e.filename2);
 	return error;
 }
 
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 62062a6..d1b96f0 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -223,6 +223,25 @@ bool tomoyo_memory_ok(void *ptr)
 }
 
 /**
+ * tomoyo_commit_ok - Check memory quota.
+ *
+ * @data:   Data to copy from.
+ * @size:   Size in byte.
+ *
+ * Returns pointer to allocated memory on success, NULL otherwise.
+ */
+void *tomoyo_commit_ok(void *data, const unsigned int size)
+{
+	void *ptr = kzalloc(size, GFP_NOFS);
+	if (tomoyo_memory_ok(ptr)) {
+		memmove(ptr, data, size);
+		memset(data, 0, size);
+		return ptr;
+	}
+	return NULL;
+}
+
+/**
  * tomoyo_memory_free - Free memory for elements.
  *
  * @ptr:  Pointer to allocated memory.