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/fs_struct.h> 13 #include <linux/f2fs_fs.h> 14 #include "f2fs.h" 15 #include "xattr.h" 16 #include "acl.h" 17 18 static inline size_t f2fs_acl_size(int count) 19 { 20 if (count <= 4) { 21 return sizeof(struct f2fs_acl_header) + 22 count * sizeof(struct f2fs_acl_entry_short); 23 } else { 24 return sizeof(struct f2fs_acl_header) + 25 4 * sizeof(struct f2fs_acl_entry_short) + 26 (count - 4) * sizeof(struct f2fs_acl_entry); 27 } 28 } 29 30 static inline int f2fs_acl_count(size_t size) 31 { 32 ssize_t s; 33 34 size -= sizeof(struct f2fs_acl_header); 35 s = size - 4 * sizeof(struct f2fs_acl_entry_short); 36 if (s < 0) { 37 if (size % sizeof(struct f2fs_acl_entry_short)) 38 return -1; 39 return size / sizeof(struct f2fs_acl_entry_short); 40 } else { 41 if (s % sizeof(struct f2fs_acl_entry)) 42 return -1; 43 return s / sizeof(struct f2fs_acl_entry) + 4; 44 } 45 } 46 47 static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) 48 { 49 int i, count; 50 struct posix_acl *acl; 51 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; 52 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); 53 const char *end = value + size; 54 55 if (size < sizeof(struct f2fs_acl_header)) 56 return ERR_PTR(-EINVAL); 57 58 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) 59 return ERR_PTR(-EINVAL); 60 61 count = f2fs_acl_count(size); 62 if (count < 0) 63 return ERR_PTR(-EINVAL); 64 if (count == 0) 65 return NULL; 66 67 acl = posix_acl_alloc(count, GFP_NOFS); 68 if (!acl) 69 return ERR_PTR(-ENOMEM); 70 71 for (i = 0; i < count; i++) { 72 73 if ((char *)entry > end) 74 goto fail; 75 76 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag); 77 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); 78 79 switch (acl->a_entries[i].e_tag) { 80 case ACL_USER_OBJ: 81 case ACL_GROUP_OBJ: 82 case ACL_MASK: 83 case ACL_OTHER: 84 entry = (struct f2fs_acl_entry *)((char *)entry + 85 sizeof(struct f2fs_acl_entry_short)); 86 break; 87 88 case ACL_USER: 89 acl->a_entries[i].e_uid = 90 make_kuid(&init_user_ns, 91 le32_to_cpu(entry->e_id)); 92 entry = (struct f2fs_acl_entry *)((char *)entry + 93 sizeof(struct f2fs_acl_entry)); 94 break; 95 case ACL_GROUP: 96 acl->a_entries[i].e_gid = 97 make_kgid(&init_user_ns, 98 le32_to_cpu(entry->e_id)); 99 entry = (struct f2fs_acl_entry *)((char *)entry + 100 sizeof(struct f2fs_acl_entry)); 101 break; 102 default: 103 goto fail; 104 } 105 } 106 if ((char *)entry != end) 107 goto fail; 108 return acl; 109 fail: 110 posix_acl_release(acl); 111 return ERR_PTR(-EINVAL); 112 } 113 114 static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi, 115 const struct posix_acl *acl, size_t *size) 116 { 117 struct f2fs_acl_header *f2fs_acl; 118 struct f2fs_acl_entry *entry; 119 int i; 120 121 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + 122 acl->a_count * sizeof(struct f2fs_acl_entry), 123 GFP_NOFS); 124 if (!f2fs_acl) 125 return ERR_PTR(-ENOMEM); 126 127 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); 128 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); 129 130 for (i = 0; i < acl->a_count; i++) { 131 132 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); 133 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); 134 135 switch (acl->a_entries[i].e_tag) { 136 case ACL_USER: 137 entry->e_id = cpu_to_le32( 138 from_kuid(&init_user_ns, 139 acl->a_entries[i].e_uid)); 140 entry = (struct f2fs_acl_entry *)((char *)entry + 141 sizeof(struct f2fs_acl_entry)); 142 break; 143 case ACL_GROUP: 144 entry->e_id = cpu_to_le32( 145 from_kgid(&init_user_ns, 146 acl->a_entries[i].e_gid)); 147 entry = (struct f2fs_acl_entry *)((char *)entry + 148 sizeof(struct f2fs_acl_entry)); 149 break; 150 case ACL_USER_OBJ: 151 case ACL_GROUP_OBJ: 152 case ACL_MASK: 153 case ACL_OTHER: 154 entry = (struct f2fs_acl_entry *)((char *)entry + 155 sizeof(struct f2fs_acl_entry_short)); 156 break; 157 default: 158 goto fail; 159 } 160 } 161 *size = f2fs_acl_size(acl->a_count); 162 return (void *)f2fs_acl; 163 164 fail: 165 kfree(f2fs_acl); 166 return ERR_PTR(-EINVAL); 167 } 168 169 static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, 170 struct folio *dfolio) 171 { 172 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 173 void *value = NULL; 174 struct posix_acl *acl; 175 int retval; 176 177 if (type == ACL_TYPE_ACCESS) 178 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 179 180 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dfolio); 181 if (retval > 0) { 182 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); 183 if (!value) 184 return ERR_PTR(-ENOMEM); 185 retval = f2fs_getxattr(inode, name_index, "", value, 186 retval, dfolio); 187 } 188 189 if (retval > 0) 190 acl = f2fs_acl_from_disk(value, retval); 191 else if (retval == -ENODATA) 192 acl = NULL; 193 else 194 acl = ERR_PTR(retval); 195 kfree(value); 196 197 return acl; 198 } 199 200 struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu) 201 { 202 if (rcu) 203 return ERR_PTR(-ECHILD); 204 205 return __f2fs_get_acl(inode, type, NULL); 206 } 207 208 static int f2fs_acl_update_mode(struct mnt_idmap *idmap, 209 struct inode *inode, umode_t *mode_p, 210 struct posix_acl **acl) 211 { 212 umode_t mode = inode->i_mode; 213 int error; 214 215 if (is_inode_flag_set(inode, FI_ACL_MODE)) 216 mode = F2FS_I(inode)->i_acl_mode; 217 218 error = posix_acl_equiv_mode(*acl, &mode); 219 if (error < 0) 220 return error; 221 if (error == 0) 222 *acl = NULL; 223 if (!in_group_or_capable(idmap, inode, i_gid_into_vfsgid(idmap, inode))) 224 mode &= ~S_ISGID; 225 *mode_p = mode; 226 return 0; 227 } 228 229 static int __f2fs_set_acl(struct mnt_idmap *idmap, 230 struct inode *inode, int type, 231 struct posix_acl *acl, struct folio *ifolio) 232 { 233 int name_index; 234 void *value = NULL; 235 size_t size = 0; 236 int error; 237 umode_t mode = inode->i_mode; 238 239 switch (type) { 240 case ACL_TYPE_ACCESS: 241 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 242 if (acl && !ifolio) { 243 error = f2fs_acl_update_mode(idmap, inode, &mode, &acl); 244 if (error) 245 return error; 246 set_acl_inode(inode, mode); 247 } 248 break; 249 250 case ACL_TYPE_DEFAULT: 251 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 252 if (!S_ISDIR(inode->i_mode)) 253 return acl ? -EACCES : 0; 254 break; 255 256 default: 257 return -EINVAL; 258 } 259 260 if (acl) { 261 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 262 if (IS_ERR(value)) { 263 clear_inode_flag(inode, FI_ACL_MODE); 264 return PTR_ERR(value); 265 } 266 } 267 268 error = f2fs_setxattr(inode, name_index, "", value, size, ifolio, 0); 269 270 kfree(value); 271 if (!error) 272 set_cached_acl(inode, type, acl); 273 274 clear_inode_flag(inode, FI_ACL_MODE); 275 return error; 276 } 277 278 int f2fs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 279 struct posix_acl *acl, int type) 280 { 281 struct inode *inode = d_inode(dentry); 282 283 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) 284 return -EIO; 285 286 return __f2fs_set_acl(idmap, inode, type, acl, NULL); 287 } 288 289 /* 290 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 291 * are copied from posix_acl.c 292 */ 293 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 294 gfp_t flags) 295 { 296 struct posix_acl *clone = NULL; 297 298 if (acl) { 299 clone = kmemdup(acl, struct_size(acl, a_entries, acl->a_count), 300 flags); 301 if (clone) 302 refcount_set(&clone->a_refcount, 1); 303 } 304 return clone; 305 } 306 307 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 308 { 309 struct posix_acl_entry *pa, *pe; 310 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 311 umode_t mode = *mode_p; 312 int not_equiv = 0; 313 314 /* assert(atomic_read(acl->a_refcount) == 1); */ 315 316 FOREACH_ACL_ENTRY(pa, acl, pe) { 317 switch (pa->e_tag) { 318 case ACL_USER_OBJ: 319 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 320 mode &= (pa->e_perm << 6) | ~S_IRWXU; 321 break; 322 323 case ACL_USER: 324 case ACL_GROUP: 325 not_equiv = 1; 326 break; 327 328 case ACL_GROUP_OBJ: 329 group_obj = pa; 330 break; 331 332 case ACL_OTHER: 333 pa->e_perm &= mode | ~S_IRWXO; 334 mode &= pa->e_perm | ~S_IRWXO; 335 break; 336 337 case ACL_MASK: 338 mask_obj = pa; 339 not_equiv = 1; 340 break; 341 342 default: 343 return -EIO; 344 } 345 } 346 347 if (mask_obj) { 348 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 349 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 350 } else { 351 if (!group_obj) 352 return -EIO; 353 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 354 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 355 } 356 357 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 358 return not_equiv; 359 } 360 361 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 362 struct posix_acl **default_acl, struct posix_acl **acl, 363 struct folio *dfolio) 364 { 365 struct posix_acl *p; 366 struct posix_acl *clone; 367 int ret; 368 369 *acl = NULL; 370 *default_acl = NULL; 371 372 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 373 return 0; 374 375 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dfolio); 376 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 377 *mode &= ~current_umask(); 378 return 0; 379 } 380 if (IS_ERR(p)) 381 return PTR_ERR(p); 382 383 clone = f2fs_acl_clone(p, GFP_NOFS); 384 if (!clone) { 385 ret = -ENOMEM; 386 goto release_acl; 387 } 388 389 ret = f2fs_acl_create_masq(clone, mode); 390 if (ret < 0) 391 goto release_clone; 392 393 if (ret == 0) 394 posix_acl_release(clone); 395 else 396 *acl = clone; 397 398 if (!S_ISDIR(*mode)) 399 posix_acl_release(p); 400 else 401 *default_acl = p; 402 403 return 0; 404 405 release_clone: 406 posix_acl_release(clone); 407 release_acl: 408 posix_acl_release(p); 409 return ret; 410 } 411 412 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct folio *ifolio, 413 struct folio *dfolio) 414 { 415 struct posix_acl *default_acl = NULL, *acl = NULL; 416 int error; 417 418 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dfolio); 419 if (error) 420 return error; 421 422 f2fs_mark_inode_dirty_sync(inode, true); 423 424 if (default_acl) { 425 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_DEFAULT, 426 default_acl, ifolio); 427 posix_acl_release(default_acl); 428 } else { 429 inode->i_default_acl = NULL; 430 } 431 if (acl) { 432 if (!error) 433 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_ACCESS, 434 acl, ifolio); 435 posix_acl_release(acl); 436 } else { 437 inode->i_acl = NULL; 438 } 439 440 return error; 441 } 442