diff options
Diffstat (limited to 'security/tomoyo/memory.c')
| -rw-r--r-- | security/tomoyo/memory.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/security/tomoyo/memory.c b/security/tomoyo/memory.c new file mode 100644 index 000000000..2e7fcfa92 --- /dev/null +++ b/security/tomoyo/memory.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/memory.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/hash.h> +#include <linux/slab.h> +#include "common.h" + +/** + * tomoyo_warn_oom - Print out of memory warning message. + * + * @function: Function's name. + */ +void tomoyo_warn_oom(const char *function) +{ + /* Reduce error messages. */ + static pid_t tomoyo_last_pid; + const pid_t pid = current->pid; + + if (tomoyo_last_pid != pid) { + pr_warn("ERROR: Out of memory at %s.\n", function); + tomoyo_last_pid = pid; + } + if (!tomoyo_policy_loaded) + panic("MAC Initialization failed.\n"); +} + +/* Memoy currently used by policy/audit log/query. */ +unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; +/* Memory quota for "policy"/"audit log"/"query". */ +unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; + +/** + * tomoyo_memory_ok - Check memory quota. + * + * @ptr: Pointer to allocated memory. + * + * Returns true on success, false otherwise. + * + * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. + * + * Caller holds tomoyo_policy_lock mutex. + */ +bool tomoyo_memory_ok(void *ptr) +{ + if (ptr) { + const size_t s = ksize(ptr); + + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; + if (!tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= + tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]) + return true; + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; + } + tomoyo_warn_oom(__func__); + return false; +} + +/** + * tomoyo_commit_ok - Check memory quota. + * + * @data: Data to copy from. + * @size: Size in byte. + * + * Returns pointer to allocated memory on success, NULL otherwise. + * @data is zero-cleared on success. + * + * Caller holds tomoyo_policy_lock mutex. + */ +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; + } + kfree(ptr); + return NULL; +} + +/** + * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". + * + * @param: Pointer to "struct tomoyo_acl_param". + * @idx: Index number. + * + * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. + */ +struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, + const u8 idx) +{ + struct tomoyo_group e = { }; + struct tomoyo_group *group = NULL; + struct list_head *list; + const char *group_name = tomoyo_read_token(param); + bool found = false; + + if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP) + return NULL; + e.group_name = tomoyo_get_name(group_name); + if (!e.group_name) + return NULL; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + list = ¶m->ns->group_list[idx]; + list_for_each_entry(group, list, head.list) { + if (e.group_name != group->group_name || + atomic_read(&group->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&group->head.users); + found = true; + break; + } + if (!found) { + struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e)); + + if (entry) { + INIT_LIST_HEAD(&entry->member_list); + atomic_set(&entry->head.users, 1); + list_add_tail_rcu(&entry->head.list, list); + group = entry; + found = true; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + tomoyo_put_name(e.group_name); + return found ? group : NULL; +} + +/* + * tomoyo_name_list is used for holding string data used by TOMOYO. + * Since same string data is likely used for multiple times (e.g. + * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of + * "const struct tomoyo_path_info *". + */ +struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; + +/** + * 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_get_name(const char *name) +{ + struct tomoyo_name *ptr; + unsigned int hash; + int len; + struct list_head *head; + + if (!name) + return NULL; + len = strlen(name) + 1; + hash = full_name_hash(NULL, (const unsigned char *) name, len - 1); + head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return NULL; + list_for_each_entry(ptr, head, head.list) { + if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) || + atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&ptr->head.users); + goto out; + } + ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS); + if (tomoyo_memory_ok(ptr)) { + ptr->entry.name = ((char *) ptr) + sizeof(*ptr); + memmove((char *) ptr->entry.name, name, len); + atomic_set(&ptr->head.users, 1); + tomoyo_fill_path_info(&ptr->entry); + list_add_tail(&ptr->head.list, head); + } else { + kfree(ptr); + ptr = NULL; + } +out: + mutex_unlock(&tomoyo_policy_lock); + return ptr ? &ptr->entry : NULL; +} + +/* Initial namespace.*/ +struct tomoyo_policy_namespace tomoyo_kernel_namespace; + +/** + * tomoyo_mm_init - Initialize mm related code. + */ +void __init tomoyo_mm_init(void) +{ + int idx; + + for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) + INIT_LIST_HEAD(&tomoyo_name_list[idx]); + tomoyo_kernel_namespace.name = "<kernel>"; + tomoyo_init_policy_namespace(&tomoyo_kernel_namespace); + tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace; + INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list); + tomoyo_kernel_domain.domainname = tomoyo_get_name("<kernel>"); + list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list); +} |