1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/f2fs/acl.c 4 * 5 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 6 * http://www.samsung.com/ 7 * 8 * Portions of this code from linux/fs/ext2/acl.c 9 * 10 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 11 */ 12 #include <linux/f2fs_fs.h> 13 #include "f2fs.h" 14 #include "xattr.h" 15 #include "acl.h" 16 17 static inline size_t f2fs_acl_size(int count) 18 { 19 if (count <= 4) { 20 return sizeof(struct f2fs_acl_header) + 21 count * sizeof(struct f2fs_acl_entry_short); 22 } else { 23 return sizeof(struct f2fs_acl_header) + 24 4 * sizeof(struct f2fs_acl_entry_short) + 25 (count - 4) * sizeof(struct f2fs_acl_entry); 26 } 27 } 28 29 static inline int f2fs_acl_count(size_t size) 30 { 31 ssize_t s; 32 33 size -= sizeof(struct f2fs_acl_header); 34 s = size - 4 * sizeof(struct f2fs_acl_entry_short); 35 if (s < 0) { 36 if (size % sizeof(struct f2fs_acl_entry_short)) 37 return -1; 38 return size / sizeof(struct f2fs_acl_entry_short); 39 } else { 40 if (s % sizeof(struct f2fs_acl_entry)) 41 return -1; 42 return s / sizeof(struct f2fs_acl_entry) + 4; 43 } 44 } 45 46 static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) 47 { 48 int i, count; 49 struct posix_acl *acl; 50 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; 51 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); 52 const char *end = value + size; 53 54 if (size < sizeof(struct f2fs_acl_header)) 55 return ERR_PTR(-EINVAL); 56 57 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) 58 return ERR_PTR(-EINVAL); 59 60 count = f2fs_acl_count(size); 61 if (count < 0) 62 return ERR_PTR(-EINVAL); 63 if (count == 0) 64 return NULL; 65 66 acl = posix_acl_alloc(count, GFP_NOFS); 67 if (!acl) 68 return ERR_PTR(-ENOMEM); 69 70 for (i = 0; i < count; i++) { 71 72 if ((char *)entry > end) 73 goto fail; 74 75 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag); 76 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); 77 78 switch (acl->a_entries[i].e_tag) { 79 case ACL_USER_OBJ: 80 case ACL_GROUP_OBJ: 81 case ACL_MASK: 82 case ACL_OTHER: 83 entry = (struct f2fs_acl_entry *)((char *)entry + 84 sizeof(struct f2fs_acl_entry_short)); 85 break; 86 87 case ACL_USER: 88 acl->a_entries[i].e_uid = 89 make_kuid(&init_user_ns, 90 le32_to_cpu(entry->e_id)); 91 entry = (struct f2fs_acl_entry *)((char *)entry + 92 sizeof(struct f2fs_acl_entry)); 93 break; 94 case ACL_GROUP: 95 acl->a_entries[i].e_gid = 96 make_kgid(&init_user_ns, 97 le32_to_cpu(entry->e_id)); 98 entry = (struct f2fs_acl_entry *)((char *)entry + 99 sizeof(struct f2fs_acl_entry)); 100 break; 101 default: 102 goto fail; 103 } 104 } 105 if ((char *)entry != end) 106 goto fail; 107 return acl; 108 fail: 109 posix_acl_release(acl); 110 return ERR_PTR(-EINVAL); 111 } 112 113 static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi, 114 const struct posix_acl *acl, size_t *size) 115 { 116 struct f2fs_acl_header *f2fs_acl; 117 struct f2fs_acl_entry *entry; 118 int i; 119 120 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + 121 acl->a_count * sizeof(struct f2fs_acl_entry), 122 GFP_NOFS); 123 if (!f2fs_acl) 124 return ERR_PTR(-ENOMEM); 125 126 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); 127 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); 128 129 for (i = 0; i < acl->a_count; i++) { 130 131 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); 132 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); 133 134 switch (acl->a_entries[i].e_tag) { 135 case ACL_USER: 136 entry->e_id = cpu_to_le32( 137 from_kuid(&init_user_ns, 138 acl->a_entries[i].e_uid)); 139 entry = (struct f2fs_acl_entry *)((char *)entry + 140 sizeof(struct f2fs_acl_entry)); 141 break; 142 case ACL_GROUP: 143 entry->e_id = cpu_to_le32( 144 from_kgid(&init_user_ns, 145 acl->a_entries[i].e_gid)); 146 entry = (struct f2fs_acl_entry *)((char *)entry + 147 sizeof(struct f2fs_acl_entry)); 148 break; 149 case ACL_USER_OBJ: 150 case ACL_GROUP_OBJ: 151 case ACL_MASK: 152 case ACL_OTHER: 153 entry = (struct f2fs_acl_entry *)((char *)entry + 154 sizeof(struct f2fs_acl_entry_short)); 155 break; 156 default: 157 goto fail; 158 } 159 } 160 *size = f2fs_acl_size(acl->a_count); 161 return (void *)f2fs_acl; 162 163 fail: 164 kfree(f2fs_acl); 165 return ERR_PTR(-EINVAL); 166 } 167 168 static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, 169 struct page *dpage) 170 { 171 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 172 void *value = NULL; 173 struct posix_acl *acl; 174 int retval; 175 176 if (type == ACL_TYPE_ACCESS) 177 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 178 179 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage); 180 if (retval > 0) { 181 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); 182 if (!value) 183 return ERR_PTR(-ENOMEM); 184 retval = f2fs_getxattr(inode, name_index, "", value, 185 retval, dpage); 186 } 187 188 if (retval > 0) 189 acl = f2fs_acl_from_disk(value, retval); 190 else if (retval == -ENODATA) 191 acl = NULL; 192 else 193 acl = ERR_PTR(retval); 194 kfree(value); 195 196 return acl; 197 } 198 199 struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu) 200 { 201 if (rcu) 202 return ERR_PTR(-ECHILD); 203 204 return __f2fs_get_acl(inode, type, NULL); 205 } 206 207 static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p, 208 struct posix_acl **acl) 209 { 210 umode_t mode = inode->i_mode; 211 int error; 212 213 if (is_inode_flag_set(inode, FI_ACL_MODE)) 214 mode = F2FS_I(inode)->i_acl_mode; 215 216 error = posix_acl_equiv_mode(*acl, &mode); 217 if (error < 0) 218 return error; 219 if (error == 0) 220 *acl = NULL; 221 if (!in_group_p(i_gid_into_mnt(&init_user_ns, inode)) && 222 !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID)) 223 mode &= ~S_ISGID; 224 *mode_p = mode; 225 return 0; 226 } 227 228 static int __f2fs_set_acl(struct inode *inode, int type, 229 struct posix_acl *acl, struct page *ipage) 230 { 231 int name_index; 232 void *value = NULL; 233 size_t size = 0; 234 int error; 235 umode_t mode = inode->i_mode; 236 237 switch (type) { 238 case ACL_TYPE_ACCESS: 239 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 240 if (acl && !ipage) { 241 error = f2fs_acl_update_mode(inode, &mode, &acl); 242 if (error) 243 return error; 244 set_acl_inode(inode, mode); 245 } 246 break; 247 248 case ACL_TYPE_DEFAULT: 249 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 250 if (!S_ISDIR(inode->i_mode)) 251 return acl ? -EACCES : 0; 252 break; 253 254 default: 255 return -EINVAL; 256 } 257 258 if (acl) { 259 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 260 if (IS_ERR(value)) { 261 clear_inode_flag(inode, FI_ACL_MODE); 262 return PTR_ERR(value); 263 } 264 } 265 266 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); 267 268 kfree(value); 269 if (!error) 270 set_cached_acl(inode, type, acl); 271 272 clear_inode_flag(inode, FI_ACL_MODE); 273 return error; 274 } 275 276 int f2fs_set_acl(struct user_namespace *mnt_userns, struct inode *inode, 277 struct posix_acl *acl, int type) 278 { 279 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) 280 return -EIO; 281 282 return __f2fs_set_acl(inode, type, acl, NULL); 283 } 284 285 /* 286 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 287 * are copied from posix_acl.c 288 */ 289 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 290 gfp_t flags) 291 { 292 struct posix_acl *clone = NULL; 293 294 if (acl) { 295 int size = sizeof(struct posix_acl) + acl->a_count * 296 sizeof(struct posix_acl_entry); 297 clone = kmemdup(acl, size, flags); 298 if (clone) 299 refcount_set(&clone->a_refcount, 1); 300 } 301 return clone; 302 } 303 304 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 305 { 306 struct posix_acl_entry *pa, *pe; 307 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 308 umode_t mode = *mode_p; 309 int not_equiv = 0; 310 311 /* assert(atomic_read(acl->a_refcount) == 1); */ 312 313 FOREACH_ACL_ENTRY(pa, acl, pe) { 314 switch (pa->e_tag) { 315 case ACL_USER_OBJ: 316 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 317 mode &= (pa->e_perm << 6) | ~S_IRWXU; 318 break; 319 320 case ACL_USER: 321 case ACL_GROUP: 322 not_equiv = 1; 323 break; 324 325 case ACL_GROUP_OBJ: 326 group_obj = pa; 327 break; 328 329 case ACL_OTHER: 330 pa->e_perm &= mode | ~S_IRWXO; 331 mode &= pa->e_perm | ~S_IRWXO; 332 break; 333 334 case ACL_MASK: 335 mask_obj = pa; 336 not_equiv = 1; 337 break; 338 339 default: 340 return -EIO; 341 } 342 } 343 344 if (mask_obj) { 345 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 346 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 347 } else { 348 if (!group_obj) 349 return -EIO; 350 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 351 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 352 } 353 354 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 355 return not_equiv; 356 } 357 358 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 359 struct posix_acl **default_acl, struct posix_acl **acl, 360 struct page *dpage) 361 { 362 struct posix_acl *p; 363 struct posix_acl *clone; 364 int ret; 365 366 *acl = NULL; 367 *default_acl = NULL; 368 369 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 370 return 0; 371 372 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); 373 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 374 *mode &= ~current_umask(); 375 return 0; 376 } 377 if (IS_ERR(p)) 378 return PTR_ERR(p); 379 380 clone = f2fs_acl_clone(p, GFP_NOFS); 381 if (!clone) { 382 ret = -ENOMEM; 383 goto release_acl; 384 } 385 386 ret = f2fs_acl_create_masq(clone, mode); 387 if (ret < 0) 388 goto release_clone; 389 390 if (ret == 0) 391 posix_acl_release(clone); 392 else 393 *acl = clone; 394 395 if (!S_ISDIR(*mode)) 396 posix_acl_release(p); 397 else 398 *default_acl = p; 399 400 return 0; 401 402 release_clone: 403 posix_acl_release(clone); 404 release_acl: 405 posix_acl_release(p); 406 return ret; 407 } 408 409 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, 410 struct page *dpage) 411 { 412 struct posix_acl *default_acl = NULL, *acl = NULL; 413 int error; 414 415 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); 416 if (error) 417 return error; 418 419 f2fs_mark_inode_dirty_sync(inode, true); 420 421 if (default_acl) { 422 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, 423 ipage); 424 posix_acl_release(default_acl); 425 } else { 426 inode->i_default_acl = NULL; 427 } 428 if (acl) { 429 if (!error) 430 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, 431 ipage); 432 posix_acl_release(acl); 433 } else { 434 inode->i_acl = NULL; 435 } 436 437 return error; 438 } 439