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