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 user_namespace *mnt_userns, 208 struct inode *inode, umode_t *mode_p, 209 struct posix_acl **acl) 210 { 211 umode_t mode = inode->i_mode; 212 int error; 213 214 if (is_inode_flag_set(inode, FI_ACL_MODE)) 215 mode = F2FS_I(inode)->i_acl_mode; 216 217 error = posix_acl_equiv_mode(*acl, &mode); 218 if (error < 0) 219 return error; 220 if (error == 0) 221 *acl = NULL; 222 if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) && 223 !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID)) 224 mode &= ~S_ISGID; 225 *mode_p = mode; 226 return 0; 227 } 228 229 static int __f2fs_set_acl(struct user_namespace *mnt_userns, 230 struct inode *inode, int type, 231 struct posix_acl *acl, struct page *ipage) 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 && !ipage) { 243 error = f2fs_acl_update_mode(mnt_userns, inode, 244 &mode, &acl); 245 if (error) 246 return error; 247 set_acl_inode(inode, mode); 248 } 249 break; 250 251 case ACL_TYPE_DEFAULT: 252 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 253 if (!S_ISDIR(inode->i_mode)) 254 return acl ? -EACCES : 0; 255 break; 256 257 default: 258 return -EINVAL; 259 } 260 261 if (acl) { 262 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 263 if (IS_ERR(value)) { 264 clear_inode_flag(inode, FI_ACL_MODE); 265 return PTR_ERR(value); 266 } 267 } 268 269 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); 270 271 kfree(value); 272 if (!error) 273 set_cached_acl(inode, type, acl); 274 275 clear_inode_flag(inode, FI_ACL_MODE); 276 return error; 277 } 278 279 int f2fs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, 280 struct posix_acl *acl, int type) 281 { 282 struct inode *inode = d_inode(dentry); 283 284 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) 285 return -EIO; 286 287 return __f2fs_set_acl(mnt_userns, inode, type, acl, NULL); 288 } 289 290 /* 291 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 292 * are copied from posix_acl.c 293 */ 294 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 295 gfp_t flags) 296 { 297 struct posix_acl *clone = NULL; 298 299 if (acl) { 300 int size = sizeof(struct posix_acl) + acl->a_count * 301 sizeof(struct posix_acl_entry); 302 clone = kmemdup(acl, size, flags); 303 if (clone) 304 refcount_set(&clone->a_refcount, 1); 305 } 306 return clone; 307 } 308 309 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 310 { 311 struct posix_acl_entry *pa, *pe; 312 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 313 umode_t mode = *mode_p; 314 int not_equiv = 0; 315 316 /* assert(atomic_read(acl->a_refcount) == 1); */ 317 318 FOREACH_ACL_ENTRY(pa, acl, pe) { 319 switch (pa->e_tag) { 320 case ACL_USER_OBJ: 321 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 322 mode &= (pa->e_perm << 6) | ~S_IRWXU; 323 break; 324 325 case ACL_USER: 326 case ACL_GROUP: 327 not_equiv = 1; 328 break; 329 330 case ACL_GROUP_OBJ: 331 group_obj = pa; 332 break; 333 334 case ACL_OTHER: 335 pa->e_perm &= mode | ~S_IRWXO; 336 mode &= pa->e_perm | ~S_IRWXO; 337 break; 338 339 case ACL_MASK: 340 mask_obj = pa; 341 not_equiv = 1; 342 break; 343 344 default: 345 return -EIO; 346 } 347 } 348 349 if (mask_obj) { 350 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 351 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 352 } else { 353 if (!group_obj) 354 return -EIO; 355 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 356 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 357 } 358 359 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 360 return not_equiv; 361 } 362 363 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 364 struct posix_acl **default_acl, struct posix_acl **acl, 365 struct page *dpage) 366 { 367 struct posix_acl *p; 368 struct posix_acl *clone; 369 int ret; 370 371 *acl = NULL; 372 *default_acl = NULL; 373 374 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 375 return 0; 376 377 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); 378 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 379 *mode &= ~current_umask(); 380 return 0; 381 } 382 if (IS_ERR(p)) 383 return PTR_ERR(p); 384 385 clone = f2fs_acl_clone(p, GFP_NOFS); 386 if (!clone) { 387 ret = -ENOMEM; 388 goto release_acl; 389 } 390 391 ret = f2fs_acl_create_masq(clone, mode); 392 if (ret < 0) 393 goto release_clone; 394 395 if (ret == 0) 396 posix_acl_release(clone); 397 else 398 *acl = clone; 399 400 if (!S_ISDIR(*mode)) 401 posix_acl_release(p); 402 else 403 *default_acl = p; 404 405 return 0; 406 407 release_clone: 408 posix_acl_release(clone); 409 release_acl: 410 posix_acl_release(p); 411 return ret; 412 } 413 414 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, 415 struct page *dpage) 416 { 417 struct posix_acl *default_acl = NULL, *acl = NULL; 418 int error; 419 420 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); 421 if (error) 422 return error; 423 424 f2fs_mark_inode_dirty_sync(inode, true); 425 426 if (default_acl) { 427 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_DEFAULT, default_acl, 428 ipage); 429 posix_acl_release(default_acl); 430 } else { 431 inode->i_default_acl = NULL; 432 } 433 if (acl) { 434 if (!error) 435 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_ACCESS, acl, 436 ipage); 437 posix_acl_release(acl); 438 } else { 439 inode->i_acl = NULL; 440 } 441 442 return error; 443 } 444