1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * security/tomoyo/memory.c |
4 | * |
5 | * Copyright (C) 2005-2011 NTT DATA CORPORATION |
6 | */ |
7 | |
8 | #include <linux/hash.h> |
9 | #include <linux/slab.h> |
10 | #include "common.h" |
11 | |
12 | /** |
13 | * tomoyo_warn_oom - Print out of memory warning message. |
14 | * |
15 | * @function: Function's name. |
16 | */ |
17 | void tomoyo_warn_oom(const char *function) |
18 | { |
19 | /* Reduce error messages. */ |
20 | static pid_t tomoyo_last_pid; |
21 | const pid_t pid = current->pid; |
22 | |
23 | if (tomoyo_last_pid != pid) { |
24 | pr_warn("ERROR: Out of memory at %s.\n" , function); |
25 | tomoyo_last_pid = pid; |
26 | } |
27 | if (!tomoyo_policy_loaded) |
28 | panic(fmt: "MAC Initialization failed.\n" ); |
29 | } |
30 | |
31 | /* Memoy currently used by policy/audit log/query. */ |
32 | unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; |
33 | /* Memory quota for "policy"/"audit log"/"query". */ |
34 | unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; |
35 | |
36 | /** |
37 | * tomoyo_memory_ok - Check memory quota. |
38 | * |
39 | * @ptr: Pointer to allocated memory. |
40 | * |
41 | * Returns true on success, false otherwise. |
42 | * |
43 | * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. |
44 | * |
45 | * Caller holds tomoyo_policy_lock mutex. |
46 | */ |
47 | bool tomoyo_memory_ok(void *ptr) |
48 | { |
49 | if (ptr) { |
50 | const size_t s = ksize(objp: ptr); |
51 | |
52 | tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; |
53 | if (!tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || |
54 | tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= |
55 | tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]) |
56 | return true; |
57 | tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; |
58 | } |
59 | tomoyo_warn_oom(function: __func__); |
60 | return false; |
61 | } |
62 | |
63 | /** |
64 | * tomoyo_commit_ok - Check memory quota. |
65 | * |
66 | * @data: Data to copy from. |
67 | * @size: Size in byte. |
68 | * |
69 | * Returns pointer to allocated memory on success, NULL otherwise. |
70 | * @data is zero-cleared on success. |
71 | * |
72 | * Caller holds tomoyo_policy_lock mutex. |
73 | */ |
74 | void *tomoyo_commit_ok(void *data, const unsigned int size) |
75 | { |
76 | void *ptr = kzalloc(size, GFP_NOFS | __GFP_NOWARN); |
77 | |
78 | if (tomoyo_memory_ok(ptr)) { |
79 | memmove(ptr, data, size); |
80 | memset(data, 0, size); |
81 | return ptr; |
82 | } |
83 | kfree(objp: ptr); |
84 | return NULL; |
85 | } |
86 | |
87 | /** |
88 | * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". |
89 | * |
90 | * @param: Pointer to "struct tomoyo_acl_param". |
91 | * @idx: Index number. |
92 | * |
93 | * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. |
94 | */ |
95 | struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, |
96 | const u8 idx) |
97 | { |
98 | struct tomoyo_group e = { }; |
99 | struct tomoyo_group *group = NULL; |
100 | struct list_head *list; |
101 | const char *group_name = tomoyo_read_token(param); |
102 | bool found = false; |
103 | |
104 | if (!tomoyo_correct_word(string: group_name) || idx >= TOMOYO_MAX_GROUP) |
105 | return NULL; |
106 | e.group_name = tomoyo_get_name(name: group_name); |
107 | if (!e.group_name) |
108 | return NULL; |
109 | if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
110 | goto out; |
111 | list = ¶m->ns->group_list[idx]; |
112 | list_for_each_entry(group, list, head.list) { |
113 | if (e.group_name != group->group_name || |
114 | atomic_read(v: &group->head.users) == TOMOYO_GC_IN_PROGRESS) |
115 | continue; |
116 | atomic_inc(v: &group->head.users); |
117 | found = true; |
118 | break; |
119 | } |
120 | if (!found) { |
121 | struct tomoyo_group *entry = tomoyo_commit_ok(data: &e, size: sizeof(e)); |
122 | |
123 | if (entry) { |
124 | INIT_LIST_HEAD(list: &entry->member_list); |
125 | atomic_set(v: &entry->head.users, i: 1); |
126 | list_add_tail_rcu(new: &entry->head.list, head: list); |
127 | group = entry; |
128 | found = true; |
129 | } |
130 | } |
131 | mutex_unlock(lock: &tomoyo_policy_lock); |
132 | out: |
133 | tomoyo_put_name(name: e.group_name); |
134 | return found ? group : NULL; |
135 | } |
136 | |
137 | /* |
138 | * tomoyo_name_list is used for holding string data used by TOMOYO. |
139 | * Since same string data is likely used for multiple times (e.g. |
140 | * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of |
141 | * "const struct tomoyo_path_info *". |
142 | */ |
143 | struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; |
144 | |
145 | /** |
146 | * tomoyo_get_name - Allocate permanent memory for string data. |
147 | * |
148 | * @name: The string to store into the permernent memory. |
149 | * |
150 | * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. |
151 | */ |
152 | const struct tomoyo_path_info *tomoyo_get_name(const char *name) |
153 | { |
154 | struct tomoyo_name *ptr; |
155 | unsigned int hash; |
156 | int len; |
157 | struct list_head *head; |
158 | |
159 | if (!name) |
160 | return NULL; |
161 | len = strlen(name) + 1; |
162 | hash = full_name_hash(NULL, (const unsigned char *) name, len - 1); |
163 | head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; |
164 | if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
165 | return NULL; |
166 | list_for_each_entry(ptr, head, head.list) { |
167 | if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) || |
168 | atomic_read(v: &ptr->head.users) == TOMOYO_GC_IN_PROGRESS) |
169 | continue; |
170 | atomic_inc(v: &ptr->head.users); |
171 | goto out; |
172 | } |
173 | ptr = kzalloc(size: sizeof(*ptr) + len, GFP_NOFS | __GFP_NOWARN); |
174 | if (tomoyo_memory_ok(ptr)) { |
175 | ptr->entry.name = ((char *) ptr) + sizeof(*ptr); |
176 | memmove((char *) ptr->entry.name, name, len); |
177 | atomic_set(v: &ptr->head.users, i: 1); |
178 | tomoyo_fill_path_info(ptr: &ptr->entry); |
179 | list_add_tail(new: &ptr->head.list, head); |
180 | } else { |
181 | kfree(objp: ptr); |
182 | ptr = NULL; |
183 | } |
184 | out: |
185 | mutex_unlock(lock: &tomoyo_policy_lock); |
186 | return ptr ? &ptr->entry : NULL; |
187 | } |
188 | |
189 | /* Initial namespace.*/ |
190 | struct tomoyo_policy_namespace tomoyo_kernel_namespace; |
191 | |
192 | /** |
193 | * tomoyo_mm_init - Initialize mm related code. |
194 | */ |
195 | void __init tomoyo_mm_init(void) |
196 | { |
197 | int idx; |
198 | |
199 | for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) |
200 | INIT_LIST_HEAD(list: &tomoyo_name_list[idx]); |
201 | tomoyo_kernel_namespace.name = "<kernel>" ; |
202 | tomoyo_init_policy_namespace(ns: &tomoyo_kernel_namespace); |
203 | tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace; |
204 | INIT_LIST_HEAD(list: &tomoyo_kernel_domain.acl_info_list); |
205 | tomoyo_kernel_domain.domainname = tomoyo_get_name(name: "<kernel>" ); |
206 | list_add_tail_rcu(new: &tomoyo_kernel_domain.list, head: &tomoyo_domain_list); |
207 | } |
208 | |