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TOMOYO: Add refcounter on string data.
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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>
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Tetsuo Handa authored and James Morris committed Feb 14, 2010
1 parent ca0b7df commit bf24fb0
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Showing 5 changed files with 77 additions and 40 deletions.
10 changes: 7 additions & 3 deletions security/tomoyo/common.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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. */
Expand Down Expand Up @@ -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++) {
Expand Down Expand Up @@ -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)
Expand All @@ -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;
}
Expand Down
32 changes: 23 additions & 9 deletions security/tomoyo/domain.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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)
Expand All @@ -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,
Expand All @@ -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;
}
Expand Down Expand Up @@ -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;
Expand All @@ -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)
Expand All @@ -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);
Expand All @@ -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;
}
Expand Down Expand Up @@ -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;
if (!is_delete)
Expand All @@ -640,13 +648,17 @@ static int tomoyo_update_alias_entry(const char *original_name,
}
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;
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_name(saved_original_name);
tomoyo_put_name(saved_aliased_name);
kfree(entry);
return error;
}
Expand Down Expand Up @@ -721,7 +733,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *

if (!tomoyo_is_correct_domain(domainname, __func__))
return NULL;
saved_domainname = tomoyo_save_name(domainname);
saved_domainname = tomoyo_get_name(domainname);
if (!saved_domainname)
return NULL;
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
Expand All @@ -736,13 +748,15 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
if (!found && tomoyo_memory_ok(entry)) {
INIT_LIST_HEAD(&entry->acl_info_list);
entry->domainname = saved_domainname;
saved_domainname = NULL;
entry->profile = profile;
list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
domain = entry;
entry = NULL;
found = true;
}
mutex_unlock(&tomoyo_policy_lock);
tomoyo_put_name(saved_domainname);
kfree(entry);
return found ? domain : NULL;
}
Expand Down
24 changes: 18 additions & 6 deletions security/tomoyo/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -222,7 +222,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename,

if (!tomoyo_is_correct_path(filename, 1, 0, -1, __func__))
return -EINVAL;
saved_filename = tomoyo_save_name(filename);
saved_filename = tomoyo_get_name(filename);
if (!saved_filename)
return -ENOMEM;
if (!is_delete)
Expand All @@ -237,11 +237,13 @@ static int tomoyo_update_globally_readable_entry(const char *filename,
}
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;
}
mutex_unlock(&tomoyo_policy_lock);
tomoyo_put_name(saved_filename);
kfree(entry);
return error;
}
Expand Down Expand Up @@ -365,7 +367,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
const struct tomoyo_path_info *saved_pattern;
int error = is_delete ? -ENOENT : -ENOMEM;

saved_pattern = tomoyo_save_name(pattern);
saved_pattern = tomoyo_get_name(pattern);
if (!saved_pattern)
return error;
if (!saved_pattern->is_patterned)
Expand All @@ -382,13 +384,15 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
}
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;
}
mutex_unlock(&tomoyo_policy_lock);
out:
kfree(entry);
tomoyo_put_name(saved_pattern);
return error;
}

Expand Down Expand Up @@ -518,7 +522,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,

if (!tomoyo_is_correct_path(pattern, 0, 0, 0, __func__))
return -EINVAL;
saved_pattern = tomoyo_save_name(pattern);
saved_pattern = tomoyo_get_name(pattern);
if (!saved_pattern)
return error;
if (!is_delete)
Expand All @@ -533,11 +537,13 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,
}
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;
}
mutex_unlock(&tomoyo_policy_lock);
tomoyo_put_name(saved_pattern);
kfree(entry);
return error;
}
Expand Down Expand Up @@ -867,7 +873,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
return -EINVAL;
if (!tomoyo_is_correct_path(filename, 0, 0, 0, __func__))
return -EINVAL;
saved_filename = tomoyo_save_name(filename);
saved_filename = tomoyo_get_name(filename);
if (!saved_filename)
return -ENOMEM;
if (!is_delete)
Expand Down Expand Up @@ -913,12 +919,14 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
if (perm == (1 << TOMOYO_TYPE_READ_WRITE_ACL))
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;
}
mutex_unlock(&tomoyo_policy_lock);
kfree(entry);
tomoyo_put_name(saved_filename);
return error;
}

Expand Down Expand Up @@ -952,8 +960,8 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
if (!tomoyo_is_correct_path(filename1, 0, 0, 0, __func__) ||
!tomoyo_is_correct_path(filename2, 0, 0, 0, __func__))
return -EINVAL;
saved_filename1 = tomoyo_save_name(filename1);
saved_filename2 = tomoyo_save_name(filename2);
saved_filename1 = tomoyo_get_name(filename1);
saved_filename2 = tomoyo_get_name(filename2);
if (!saved_filename1 || !saved_filename2)
goto out;
if (!is_delete)
Expand All @@ -979,13 +987,17 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
entry->head.type = TOMOYO_TYPE_DOUBLE_PATH_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;
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_name(saved_filename1);
tomoyo_put_name(saved_filename2);
kfree(entry);
return error;
}
Expand Down
30 changes: 9 additions & 21 deletions security/tomoyo/realpath.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -253,21 +253,6 @@ static unsigned int tomoyo_quota_for_savename;
#define TOMOYO_HASH_BITS 8
#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS)

/*
* tomoyo_name_entry is a structure which is used for linking
* "struct tomoyo_path_info" into tomoyo_name_list .
*
* Since tomoyo_name_list manages a list of strings which are shared by
* multiple processes (whereas "struct tomoyo_path_info" inside
* "struct tomoyo_path_info_with_data" is not shared), a reference counter will
* be added to "struct tomoyo_name_entry" rather than "struct tomoyo_path_info"
* when TOMOYO starts supporting garbage collector.
*/
struct tomoyo_name_entry {
struct list_head list;
struct tomoyo_path_info entry;
};

/*
* tomoyo_name_list is used for holding string data used by TOMOYO.
* Since same string data is likely used for multiple times (e.g.
Expand All @@ -277,13 +262,13 @@ struct tomoyo_name_entry {
static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];

/**
* tomoyo_save_name - Allocate permanent memory for string data.
* tomoyo_get_name - Allocate permanent memory for string data.
*
* @name: The string to store into the permernent memory.
*
* Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
*/
const struct tomoyo_path_info *tomoyo_save_name(const char *name)
const struct tomoyo_path_info *tomoyo_get_name(const char *name)
{
static DEFINE_MUTEX(lock);
struct tomoyo_name_entry *ptr;
Expand All @@ -299,8 +284,10 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
mutex_lock(&lock);
list_for_each_entry(ptr, head, list) {
if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name))
goto out;
if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))
continue;
atomic_inc(&ptr->users);
goto out;
}
ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
allocated_len = ptr ? ksize(ptr) : 0;
Expand All @@ -309,7 +296,7 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
> tomoyo_quota_for_savename)) {
kfree(ptr);
printk(KERN_WARNING "ERROR: Out of memory "
"for tomoyo_save_name().\n");
"for tomoyo_get_name().\n");
if (!tomoyo_policy_loaded)
panic("MAC Initialization failed.\n");
ptr = NULL;
Expand All @@ -318,6 +305,7 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
tomoyo_allocated_memory_for_savename += allocated_len;
ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
memmove((char *) ptr->entry.name, name, len);
atomic_set(&ptr->users, 1);
tomoyo_fill_path_info(&ptr->entry);
list_add_tail(&ptr->list, head);
out:
Expand All @@ -336,7 +324,7 @@ void __init tomoyo_realpath_init(void)
for (i = 0; i < TOMOYO_MAX_HASH; i++)
INIT_LIST_HEAD(&tomoyo_name_list[i]);
INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
tomoyo_kernel_domain.domainname = tomoyo_save_name(TOMOYO_ROOT_NAME);
tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
/*
* tomoyo_read_lock() is not needed because this function is
* called before the first "delete" request.
Expand Down
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