linux-stable/security/tomoyo/group.c
Tetsuo Handa 6bd5ce6089 tomoyo: Suppress RCU warning at list_for_each_entry_rcu().
John Garry has reported that allmodconfig kernel on arm64 causes flood of
"RCU-list traversed in non-reader section!!" warning. I don't know what
change caused this warning, but this warning is safe because TOMOYO uses
SRCU lock instead. Let's suppress this warning by explicitly telling that
the caller is holding SRCU lock.

Reported-and-tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2019-12-16 23:02:27 +09:00

209 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* security/tomoyo/group.c
*
* Copyright (C) 2005-2011 NTT DATA CORPORATION
*/
#include <linux/slab.h>
#include <linux/rculist.h>
#include "common.h"
/**
* tomoyo_same_path_group - Check for duplicated "struct tomoyo_path_group" entry.
*
* @a: Pointer to "struct tomoyo_acl_head".
* @b: Pointer to "struct tomoyo_acl_head".
*
* Returns true if @a == @b, false otherwise.
*/
static bool tomoyo_same_path_group(const struct tomoyo_acl_head *a,
const struct tomoyo_acl_head *b)
{
return container_of(a, struct tomoyo_path_group, head)->member_name ==
container_of(b, struct tomoyo_path_group, head)->member_name;
}
/**
* tomoyo_same_number_group - Check for duplicated "struct tomoyo_number_group" entry.
*
* @a: Pointer to "struct tomoyo_acl_head".
* @b: Pointer to "struct tomoyo_acl_head".
*
* Returns true if @a == @b, false otherwise.
*/
static bool tomoyo_same_number_group(const struct tomoyo_acl_head *a,
const struct tomoyo_acl_head *b)
{
return !memcmp(&container_of(a, struct tomoyo_number_group, head)
->number,
&container_of(b, struct tomoyo_number_group, head)
->number,
sizeof(container_of(a, struct tomoyo_number_group, head)
->number));
}
/**
* tomoyo_same_address_group - Check for duplicated "struct tomoyo_address_group" entry.
*
* @a: Pointer to "struct tomoyo_acl_head".
* @b: Pointer to "struct tomoyo_acl_head".
*
* Returns true if @a == @b, false otherwise.
*/
static bool tomoyo_same_address_group(const struct tomoyo_acl_head *a,
const struct tomoyo_acl_head *b)
{
const struct tomoyo_address_group *p1 = container_of(a, typeof(*p1),
head);
const struct tomoyo_address_group *p2 = container_of(b, typeof(*p2),
head);
return tomoyo_same_ipaddr_union(&p1->address, &p2->address);
}
/**
* tomoyo_write_group - Write "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list.
*
* @param: Pointer to "struct tomoyo_acl_param".
* @type: Type of this group.
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type)
{
struct tomoyo_group *group = tomoyo_get_group(param, type);
int error = -EINVAL;
if (!group)
return -ENOMEM;
param->list = &group->member_list;
if (type == TOMOYO_PATH_GROUP) {
struct tomoyo_path_group e = { };
e.member_name = tomoyo_get_name(tomoyo_read_token(param));
if (!e.member_name) {
error = -ENOMEM;
goto out;
}
error = tomoyo_update_policy(&e.head, sizeof(e), param,
tomoyo_same_path_group);
tomoyo_put_name(e.member_name);
} else if (type == TOMOYO_NUMBER_GROUP) {
struct tomoyo_number_group e = { };
if (param->data[0] == '@' ||
!tomoyo_parse_number_union(param, &e.number))
goto out;
error = tomoyo_update_policy(&e.head, sizeof(e), param,
tomoyo_same_number_group);
/*
* tomoyo_put_number_union() is not needed because
* param->data[0] != '@'.
*/
} else {
struct tomoyo_address_group e = { };
if (param->data[0] == '@' ||
!tomoyo_parse_ipaddr_union(param, &e.address))
goto out;
error = tomoyo_update_policy(&e.head, sizeof(e), param,
tomoyo_same_address_group);
}
out:
tomoyo_put_group(group);
return error;
}
/**
* tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
*
* @pathname: The name of pathname.
* @group: Pointer to "struct tomoyo_path_group".
*
* Returns matched member's pathname if @pathname matches pathnames in @group,
* NULL otherwise.
*
* Caller holds tomoyo_read_lock().
*/
const struct tomoyo_path_info *
tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
const struct tomoyo_group *group)
{
struct tomoyo_path_group *member;
list_for_each_entry_rcu(member, &group->member_list, head.list,
srcu_read_lock_held(&tomoyo_ss)) {
if (member->head.is_deleted)
continue;
if (!tomoyo_path_matches_pattern(pathname, member->member_name))
continue;
return member->member_name;
}
return NULL;
}
/**
* tomoyo_number_matches_group - Check whether the given number matches members of the given number group.
*
* @min: Min number.
* @max: Max number.
* @group: Pointer to "struct tomoyo_number_group".
*
* Returns true if @min and @max partially overlaps @group, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_number_matches_group(const unsigned long min,
const unsigned long max,
const struct tomoyo_group *group)
{
struct tomoyo_number_group *member;
bool matched = false;
list_for_each_entry_rcu(member, &group->member_list, head.list,
srcu_read_lock_held(&tomoyo_ss)) {
if (member->head.is_deleted)
continue;
if (min > member->number.values[1] ||
max < member->number.values[0])
continue;
matched = true;
break;
}
return matched;
}
/**
* tomoyo_address_matches_group - Check whether the given address matches members of the given address group.
*
* @is_ipv6: True if @address is an IPv6 address.
* @address: An IPv4 or IPv6 address.
* @group: Pointer to "struct tomoyo_address_group".
*
* Returns true if @address matches addresses in @group group, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address,
const struct tomoyo_group *group)
{
struct tomoyo_address_group *member;
bool matched = false;
const u8 size = is_ipv6 ? 16 : 4;
list_for_each_entry_rcu(member, &group->member_list, head.list,
srcu_read_lock_held(&tomoyo_ss)) {
if (member->head.is_deleted)
continue;
if (member->address.is_ipv6 != is_ipv6)
continue;
if (memcmp(&member->address.ip[0], address, size) > 0 ||
memcmp(address, &member->address.ip[1], size) > 0)
continue;
matched = true;
break;
}
return matched;
}