1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * security/tomoyo/securityfs_if.c 4 * 5 * Copyright (C) 2005-2011 NTT DATA CORPORATION 6 */ 7 8 #include <linux/security.h> 9 #include "common.h" 10 11 /** 12 * tomoyo_check_task_acl - Check permission for task operation. 13 * 14 * @r: Pointer to "struct tomoyo_request_info". 15 * @ptr: Pointer to "struct tomoyo_acl_info". 16 * 17 * Returns true if granted, false otherwise. 18 */ 19 static bool tomoyo_check_task_acl(struct tomoyo_request_info *r, 20 const struct tomoyo_acl_info *ptr) 21 { 22 const struct tomoyo_task_acl *acl = container_of(ptr, typeof(*acl), 23 head); 24 25 return !tomoyo_pathcmp(r->param.task.domainname, acl->domainname); 26 } 27 28 /** 29 * tomoyo_write_self - write() for /sys/kernel/security/tomoyo/self_domain interface. 30 * 31 * @file: Pointer to "struct file". 32 * @buf: Domainname to transit to. 33 * @count: Size of @buf. 34 * @ppos: Unused. 35 * 36 * Returns @count on success, negative value otherwise. 37 * 38 * If domain transition was permitted but the domain transition failed, this 39 * function returns error rather than terminating current thread with SIGKILL. 40 */ 41 static ssize_t tomoyo_write_self(struct file *file, const char __user *buf, 42 size_t count, loff_t *ppos) 43 { 44 char *data; 45 int error; 46 47 if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10) 48 return -ENOMEM; 49 data = memdup_user_nul(buf, count); 50 if (IS_ERR(data)) 51 return PTR_ERR(data); 52 tomoyo_normalize_line(data); 53 if (tomoyo_correct_domain(data)) { 54 const int idx = tomoyo_read_lock(); 55 struct tomoyo_path_info name; 56 struct tomoyo_request_info r; 57 58 name.name = data; 59 tomoyo_fill_path_info(&name); 60 /* Check "task manual_domain_transition" permission. */ 61 tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE); 62 r.param_type = TOMOYO_TYPE_MANUAL_TASK_ACL; 63 r.param.task.domainname = &name; 64 tomoyo_check_acl(&r, tomoyo_check_task_acl); 65 if (!r.granted) 66 error = -EPERM; 67 else { 68 struct tomoyo_domain_info *new_domain = 69 tomoyo_assign_domain(data, true); 70 if (!new_domain) { 71 error = -ENOENT; 72 } else { 73 struct tomoyo_task *s = tomoyo_task(current); 74 struct tomoyo_domain_info *old_domain = 75 s->domain_info; 76 77 s->domain_info = new_domain; 78 atomic_inc(&new_domain->users); 79 atomic_dec(&old_domain->users); 80 error = 0; 81 } 82 } 83 tomoyo_read_unlock(idx); 84 } else 85 error = -EINVAL; 86 kfree(data); 87 return error ? error : count; 88 } 89 90 /** 91 * tomoyo_read_self - read() for /sys/kernel/security/tomoyo/self_domain interface. 92 * 93 * @file: Pointer to "struct file". 94 * @buf: Domainname which current thread belongs to. 95 * @count: Size of @buf. 96 * @ppos: Bytes read by now. 97 * 98 * Returns read size on success, negative value otherwise. 99 */ 100 static ssize_t tomoyo_read_self(struct file *file, char __user *buf, 101 size_t count, loff_t *ppos) 102 { 103 const char *domain = tomoyo_domain()->domainname->name; 104 loff_t len = strlen(domain); 105 loff_t pos = *ppos; 106 107 if (pos >= len || !count) 108 return 0; 109 len -= pos; 110 if (count < len) 111 len = count; 112 if (copy_to_user(buf, domain + pos, len)) 113 return -EFAULT; 114 *ppos += len; 115 return len; 116 } 117 118 /* Operations for /sys/kernel/security/tomoyo/self_domain interface. */ 119 static const struct file_operations tomoyo_self_operations = { 120 .write = tomoyo_write_self, 121 .read = tomoyo_read_self, 122 }; 123 124 /** 125 * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface. 126 * 127 * @inode: Pointer to "struct inode". 128 * @file: Pointer to "struct file". 129 * 130 * Returns 0 on success, negative value otherwise. 131 */ 132 static int tomoyo_open(struct inode *inode, struct file *file) 133 { 134 const u8 key = (uintptr_t) file_inode(file)->i_private; 135 136 return tomoyo_open_control(key, file); 137 } 138 139 /** 140 * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface. 141 * 142 * @file: Pointer to "struct file". 143 * 144 */ 145 static int tomoyo_release(struct inode *inode, struct file *file) 146 { 147 tomoyo_close_control(file->private_data); 148 return 0; 149 } 150 151 /** 152 * tomoyo_poll - poll() for /sys/kernel/security/tomoyo/ interface. 153 * 154 * @file: Pointer to "struct file". 155 * @wait: Pointer to "poll_table". Maybe NULL. 156 * 157 * Returns EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM if ready to read/write, 158 * EPOLLOUT | EPOLLWRNORM otherwise. 159 */ 160 static __poll_t tomoyo_poll(struct file *file, poll_table *wait) 161 { 162 return tomoyo_poll_control(file, wait); 163 } 164 165 /** 166 * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface. 167 * 168 * @file: Pointer to "struct file". 169 * @buf: Pointer to buffer. 170 * @count: Size of @buf. 171 * @ppos: Unused. 172 * 173 * Returns bytes read on success, negative value otherwise. 174 */ 175 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count, 176 loff_t *ppos) 177 { 178 return tomoyo_read_control(file->private_data, buf, count); 179 } 180 181 /** 182 * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface. 183 * 184 * @file: Pointer to "struct file". 185 * @buf: Pointer to buffer. 186 * @count: Size of @buf. 187 * @ppos: Unused. 188 * 189 * Returns @count on success, negative value otherwise. 190 */ 191 static ssize_t tomoyo_write(struct file *file, const char __user *buf, 192 size_t count, loff_t *ppos) 193 { 194 return tomoyo_write_control(file->private_data, buf, count); 195 } 196 197 /* 198 * tomoyo_operations is a "struct file_operations" which is used for handling 199 * /sys/kernel/security/tomoyo/ interface. 200 * 201 * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR). 202 * See tomoyo_io_buffer for internals. 203 */ 204 static const struct file_operations tomoyo_operations = { 205 .open = tomoyo_open, 206 .release = tomoyo_release, 207 .poll = tomoyo_poll, 208 .read = tomoyo_read, 209 .write = tomoyo_write, 210 .llseek = noop_llseek, 211 }; 212 213 /** 214 * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory. 215 * 216 * @name: The name of the interface file. 217 * @mode: The permission of the interface file. 218 * @parent: The parent directory. 219 * @key: Type of interface. 220 * 221 * Returns nothing. 222 */ 223 static void __init tomoyo_create_entry(const char *name, const umode_t mode, 224 struct dentry *parent, const u8 key) 225 { 226 securityfs_create_file(name, mode, parent, (void *) (uintptr_t) key, 227 &tomoyo_operations); 228 } 229 230 /** 231 * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface. 232 * 233 * Returns 0. 234 */ 235 static int __init tomoyo_initerface_init(void) 236 { 237 struct tomoyo_domain_info *domain; 238 struct dentry *tomoyo_dir; 239 240 if (!tomoyo_enabled) 241 return 0; 242 domain = tomoyo_domain(); 243 /* Don't create securityfs entries unless registered. */ 244 if (domain != &tomoyo_kernel_domain) 245 return 0; 246 247 tomoyo_dir = securityfs_create_dir("tomoyo", NULL); 248 tomoyo_create_entry("query", 0600, tomoyo_dir, 249 TOMOYO_QUERY); 250 tomoyo_create_entry("domain_policy", 0600, tomoyo_dir, 251 TOMOYO_DOMAINPOLICY); 252 tomoyo_create_entry("exception_policy", 0600, tomoyo_dir, 253 TOMOYO_EXCEPTIONPOLICY); 254 tomoyo_create_entry("audit", 0400, tomoyo_dir, 255 TOMOYO_AUDIT); 256 tomoyo_create_entry(".process_status", 0600, tomoyo_dir, 257 TOMOYO_PROCESS_STATUS); 258 tomoyo_create_entry("stat", 0644, tomoyo_dir, 259 TOMOYO_STAT); 260 tomoyo_create_entry("profile", 0600, tomoyo_dir, 261 TOMOYO_PROFILE); 262 tomoyo_create_entry("manager", 0600, tomoyo_dir, 263 TOMOYO_MANAGER); 264 tomoyo_create_entry("version", 0400, tomoyo_dir, 265 TOMOYO_VERSION); 266 securityfs_create_file("self_domain", 0666, tomoyo_dir, NULL, 267 &tomoyo_self_operations); 268 tomoyo_load_builtin_policy(); 269 return 0; 270 } 271 272 fs_initcall(tomoyo_initerface_init); 273