From cd7bec6ad80188394a8ea857ff1aa3512fc2282a Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Tue, 5 Jan 2010 06:39:37 +0900 Subject: [PATCH] TOMOYO: Remove memory pool for list elements. Currently, TOMOYO allocates memory for list elements from memory pool allocated by kmalloc(PAGE_SIZE). But that makes it difficult to kfree() when garbage collector is added. Thus, remove memory pool and use kmalloc(sizeof()). Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- security/tomoyo/common.c | 41 +++++------------------- security/tomoyo/common.h | 2 -- security/tomoyo/domain.c | 58 +++++++++++----------------------- security/tomoyo/file.c | 34 ++++++++++++++------ security/tomoyo/realpath.c | 65 ++++++++++++-------------------------- security/tomoyo/realpath.h | 7 ++-- 6 files changed, 73 insertions(+), 134 deletions(-) diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index 642e0e565dfc..e331e699cf54 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -900,9 +900,11 @@ static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned ptr = tomoyo_profile_ptr[profile]; if (ptr) goto ok; - ptr = tomoyo_alloc_element(sizeof(*ptr)); - if (!ptr) + ptr = kmalloc(sizeof(*ptr), GFP_KERNEL); + if (!tomoyo_memory_ok(ptr)) { + kfree(ptr); goto ok; + } for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) ptr->value[i] = tomoyo_control_array[i].current_value; mb(); /* Avoid out-of-order execution. */ @@ -1120,6 +1122,7 @@ static int tomoyo_update_manager_entry(const char *manager, saved_manager = tomoyo_save_name(manager); if (!saved_manager) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) { if (ptr->manager != saved_manager) @@ -1132,15 +1135,16 @@ static int tomoyo_update_manager_entry(const char *manager, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->manager = saved_manager; new_entry->is_domain = is_domain; list_add_tail_rcu(&new_entry->list, &tomoyo_policy_manager_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -2147,35 +2151,6 @@ static int tomoyo_close_control(struct file *file) return 0; } -/** - * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry. - * - * @acl_type: Type of ACL entry. - * - * Returns pointer to the ACL entry on success, NULL otherwise. - */ -void *tomoyo_alloc_acl_element(const u8 acl_type) -{ - int len; - struct tomoyo_acl_info *ptr; - - switch (acl_type) { - case TOMOYO_TYPE_SINGLE_PATH_ACL: - len = sizeof(struct tomoyo_single_path_acl_record); - break; - case TOMOYO_TYPE_DOUBLE_PATH_ACL: - len = sizeof(struct tomoyo_double_path_acl_record); - break; - default: - return NULL; - } - ptr = tomoyo_alloc_element(len); - if (!ptr) - return NULL; - ptr->type = acl_type; - return ptr; -} - /** * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface. * diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h index 874abf8df43e..610a6a056828 100644 --- a/security/tomoyo/common.h +++ b/security/tomoyo/common.h @@ -376,8 +376,6 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * /* Check mode for specified functionality. */ unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain, const u8 index); -/* Allocate memory for structures. */ -void *tomoyo_alloc_acl_element(const u8 acl_type); /* Fill in "struct tomoyo_path_info" members. */ void tomoyo_fill_path_info(struct tomoyo_path_info *ptr); /* Run policy loader when /sbin/init starts. */ diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c index 7d0b0bc48201..a55a1cced58e 100644 --- a/security/tomoyo/domain.c +++ b/security/tomoyo/domain.c @@ -245,6 +245,7 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname, saved_program = tomoyo_save_name(program); if (!saved_program) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) { if (ptr->is_not != is_not || @@ -259,17 +260,18 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->domainname = saved_domainname; new_entry->program = saved_program; new_entry->is_not = is_not; new_entry->is_last_name = is_last_name; list_add_tail_rcu(&new_entry->list, &tomoyo_domain_initializer_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -461,6 +463,7 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname, saved_domainname = tomoyo_save_name(domainname); if (!saved_domainname) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) { if (ptr->is_not != is_not || @@ -475,17 +478,18 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->domainname = saved_domainname; new_entry->program = saved_program; new_entry->is_not = is_not; new_entry->is_last_name = is_last_name; list_add_tail_rcu(&new_entry->list, &tomoyo_domain_keeper_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -650,6 +654,7 @@ static int tomoyo_update_alias_entry(const char *original_name, saved_aliased_name = tomoyo_save_name(aliased_name); if (!saved_original_name || !saved_aliased_name) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) { if (ptr->original_name != saved_original_name || @@ -663,15 +668,16 @@ static int tomoyo_update_alias_entry(const char *original_name, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->original_name = saved_original_name; new_entry->aliased_name = saved_aliased_name; list_add_tail_rcu(&new_entry->list, &tomoyo_alias_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -738,7 +744,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * domainname, const u8 profile) { - struct tomoyo_domain_info *domain = NULL; + struct tomoyo_domain_info *domain; const struct tomoyo_path_info *saved_domainname; mutex_lock(&tomoyo_policy_lock); @@ -750,43 +756,17 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * saved_domainname = tomoyo_save_name(domainname); if (!saved_domainname) goto out; - /* Can I reuse memory of deleted domain? */ - list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) { - struct task_struct *p; - struct tomoyo_acl_info *ptr; - bool flag; - if (!domain->is_deleted || - domain->domainname != saved_domainname) - continue; - flag = false; - read_lock(&tasklist_lock); - for_each_process(p) { - if (tomoyo_real_domain(p) != domain) - continue; - flag = true; - break; - } - read_unlock(&tasklist_lock); - if (flag) - continue; - list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) { - ptr->type |= TOMOYO_ACL_DELETED; - } - tomoyo_set_domain_flag(domain, true, domain->flags); - domain->profile = profile; - domain->quota_warned = false; - mb(); /* Avoid out-of-order execution. */ - domain->is_deleted = false; - goto out; - } - /* No memory reusable. Create using new memory. */ - domain = tomoyo_alloc_element(sizeof(*domain)); - if (domain) { + domain = kmalloc(sizeof(*domain), GFP_KERNEL); + if (tomoyo_memory_ok(domain)) { INIT_LIST_HEAD(&domain->acl_info_list); domain->domainname = saved_domainname; domain->profile = profile; list_add_tail_rcu(&domain->list, &tomoyo_domain_list); + } else { + kfree(domain); + domain = NULL; } + out: mutex_unlock(&tomoyo_policy_lock); return domain; diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c index 5d1689d6e16c..075392c052b4 100644 --- a/security/tomoyo/file.c +++ b/security/tomoyo/file.c @@ -225,6 +225,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename, saved_filename = tomoyo_save_name(filename); if (!saved_filename) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) { if (ptr->filename != saved_filename) @@ -237,14 +238,15 @@ static int tomoyo_update_globally_readable_entry(const char *filename, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->filename = saved_filename; list_add_tail_rcu(&new_entry->list, &tomoyo_globally_readable_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -372,6 +374,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern, saved_pattern = tomoyo_save_name(pattern); if (!saved_pattern) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) { if (saved_pattern != ptr->pattern) @@ -384,14 +387,15 @@ static int tomoyo_update_file_pattern_entry(const char *pattern, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->pattern = saved_pattern; list_add_tail_rcu(&new_entry->list, &tomoyo_pattern_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -523,6 +527,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern, saved_pattern = tomoyo_save_name(pattern); if (!saved_pattern) return -ENOMEM; + new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL); mutex_lock(&tomoyo_policy_lock); list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) { if (ptr->pattern != saved_pattern) @@ -535,14 +540,15 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern, error = -ENOENT; goto out; } - new_entry = tomoyo_alloc_element(sizeof(*new_entry)); - if (!new_entry) + if (!tomoyo_memory_ok(new_entry)) goto out; new_entry->pattern = saved_pattern; list_add_tail_rcu(&new_entry->list, &tomoyo_no_rewrite_list); + new_entry = NULL; error = 0; out: mutex_unlock(&tomoyo_policy_lock); + kfree(new_entry); return error; } @@ -901,9 +907,13 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename, goto out; } /* Not found. Append it to the tail. */ - acl = tomoyo_alloc_acl_element(TOMOYO_TYPE_SINGLE_PATH_ACL); - if (!acl) + acl = kmalloc(sizeof(*acl), GFP_KERNEL); + if (!tomoyo_memory_ok(acl)) { + kfree(acl); + acl = NULL; goto out; + } + acl->head.type = TOMOYO_TYPE_SINGLE_PATH_ACL; if (perm <= 0xFFFF) acl->perm = perm; else @@ -995,9 +1005,13 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1, goto out; } /* Not found. Append it to the tail. */ - acl = tomoyo_alloc_acl_element(TOMOYO_TYPE_DOUBLE_PATH_ACL); - if (!acl) + acl = kmalloc(sizeof(*acl), GFP_KERNEL); + if (!tomoyo_memory_ok(acl)) { + kfree(acl); + acl = NULL; goto out; + } + acl->head.type = TOMOYO_TYPE_DOUBLE_PATH_ACL; acl->perm = perm; acl->filename1 = saved_filename1; acl->filename2 = saved_filename2; diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c index 9105e5e29da9..54226d5be493 100644 --- a/security/tomoyo/realpath.c +++ b/security/tomoyo/realpath.c @@ -212,57 +212,32 @@ static unsigned int tomoyo_allocated_memory_for_elements; static unsigned int tomoyo_quota_for_elements; /** - * tomoyo_alloc_element - Allocate permanent memory for structures. + * tomoyo_memory_ok - Check memory quota. * - * @size: Size in bytes. + * @ptr: Pointer to allocated memory. * - * Returns pointer to allocated memory on success, NULL otherwise. + * Returns true on success, false otherwise. * - * Memory has to be zeroed. - * The RAM is chunked, so NEVER try to kfree() the returned pointer. + * Caller holds tomoyo_policy_lock. + * Memory pointed by @ptr will be zeroed on success. */ -void *tomoyo_alloc_element(const unsigned int size) +bool tomoyo_memory_ok(void *ptr) { - static char *buf; - static DEFINE_MUTEX(lock); - static unsigned int buf_used_len = PATH_MAX; - char *ptr = NULL; - /*Assumes sizeof(void *) >= sizeof(long) is true. */ - const unsigned int word_aligned_size - = roundup(size, max(sizeof(void *), sizeof(long))); - if (word_aligned_size > PATH_MAX) - return NULL; - mutex_lock(&lock); - if (buf_used_len + word_aligned_size > PATH_MAX) { - if (!tomoyo_quota_for_elements || - tomoyo_allocated_memory_for_elements - + PATH_MAX <= tomoyo_quota_for_elements) - ptr = kzalloc(PATH_MAX, GFP_KERNEL); - if (!ptr) { - printk(KERN_WARNING "ERROR: Out of memory " - "for tomoyo_alloc_element().\n"); - if (!tomoyo_policy_loaded) - panic("MAC Initialization failed.\n"); - } else { - buf = ptr; - tomoyo_allocated_memory_for_elements += PATH_MAX; - buf_used_len = word_aligned_size; - ptr = buf; - } - } else if (word_aligned_size) { - int i; - ptr = buf + buf_used_len; - buf_used_len += word_aligned_size; - for (i = 0; i < word_aligned_size; i++) { - if (!ptr[i]) - continue; - printk(KERN_ERR "WARNING: Reserved memory was tainted! " - "The system might go wrong.\n"); - ptr[i] = '\0'; - } + int allocated_len = ptr ? ksize(ptr) : 0; + bool result = false; + if (!ptr || (tomoyo_quota_for_elements && + tomoyo_allocated_memory_for_elements + + allocated_len > tomoyo_quota_for_elements)) { + printk(KERN_WARNING "ERROR: Out of memory " + "for tomoyo_alloc_element().\n"); + if (!tomoyo_policy_loaded) + panic("MAC Initialization failed.\n"); + } else { + result = true; + tomoyo_allocated_memory_for_elements += allocated_len; + memset(ptr, 0, allocated_len); } - mutex_unlock(&lock); - return ptr; + return result; } /* Memory allocated for string data in bytes. */ diff --git a/security/tomoyo/realpath.h b/security/tomoyo/realpath.h index 78217a37960b..47b4f59dad6f 100644 --- a/security/tomoyo/realpath.h +++ b/security/tomoyo/realpath.h @@ -36,11 +36,8 @@ char *tomoyo_realpath_nofollow(const char *pathname); /* Same with tomoyo_realpath() except that the pathname is already solved. */ char *tomoyo_realpath_from_path(struct path *path); -/* - * Allocate memory for ACL entry. - * The RAM is chunked, so NEVER try to kfree() the returned pointer. - */ -void *tomoyo_alloc_element(const unsigned int size); +/* Check memory quota. */ +bool tomoyo_memory_ok(void *ptr); /* * Keep the given name on the RAM. -- 2.34.1