| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | #include <linux/capability.h> |
| 3 | #include <linux/fs.h> |
| 4 | #include <linux/posix_acl.h> |
| 5 | #include "reiserfs.h" |
| 6 | #include <linux/errno.h> |
| 7 | #include <linux/pagemap.h> |
| 8 | #include <linux/xattr.h> |
| 9 | #include <linux/slab.h> |
| 10 | #include <linux/posix_acl_xattr.h> |
| 11 | #include "xattr.h" |
| 12 | #include "acl.h" |
| 13 | #include <linux/uaccess.h> |
| 14 | |
| 15 | static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, |
| 16 | struct inode *inode, int type, |
| 17 | struct posix_acl *acl); |
| 18 | |
| 19 | |
| 20 | int |
| 21 | reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
| 22 | struct posix_acl *acl, int type) |
| 23 | { |
| 24 | int error, error2; |
| 25 | struct reiserfs_transaction_handle th; |
| 26 | size_t jcreate_blocks; |
| 27 | int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; |
| 28 | int update_mode = 0; |
| 29 | struct inode *inode = d_inode(dentry); |
| 30 | umode_t mode = inode->i_mode; |
| 31 | |
| 32 | /* |
| 33 | * Pessimism: We can't assume that anything from the xattr root up |
| 34 | * has been created. |
| 35 | */ |
| 36 | |
| 37 | jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + |
| 38 | reiserfs_xattr_nblocks(inode, size) * 2; |
| 39 | |
| 40 | reiserfs_write_lock(inode->i_sb); |
| 41 | error = journal_begin(&th, inode->i_sb, jcreate_blocks); |
| 42 | reiserfs_write_unlock(inode->i_sb); |
| 43 | if (error == 0) { |
| 44 | if (type == ACL_TYPE_ACCESS && acl) { |
| 45 | error = posix_acl_update_mode(&nop_mnt_idmap, inode, |
| 46 | &mode, &acl); |
| 47 | if (error) |
| 48 | goto unlock; |
| 49 | update_mode = 1; |
| 50 | } |
| 51 | error = __reiserfs_set_acl(&th, inode, type, acl); |
| 52 | if (!error && update_mode) |
| 53 | inode->i_mode = mode; |
| 54 | unlock: |
| 55 | reiserfs_write_lock(inode->i_sb); |
| 56 | error2 = journal_end(&th); |
| 57 | reiserfs_write_unlock(inode->i_sb); |
| 58 | if (error2) |
| 59 | error = error2; |
| 60 | } |
| 61 | |
| 62 | return error; |
| 63 | } |
| 64 | |
| 65 | /* |
| 66 | * Convert from filesystem to in-memory representation. |
| 67 | */ |
| 68 | static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) |
| 69 | { |
| 70 | const char *end = (char *)value + size; |
| 71 | int n, count; |
| 72 | struct posix_acl *acl; |
| 73 | |
| 74 | if (!value) |
| 75 | return NULL; |
| 76 | if (size < sizeof(reiserfs_acl_header)) |
| 77 | return ERR_PTR(-EINVAL); |
| 78 | if (((reiserfs_acl_header *) value)->a_version != |
| 79 | cpu_to_le32(REISERFS_ACL_VERSION)) |
| 80 | return ERR_PTR(-EINVAL); |
| 81 | value = (char *)value + sizeof(reiserfs_acl_header); |
| 82 | count = reiserfs_acl_count(size); |
| 83 | if (count < 0) |
| 84 | return ERR_PTR(-EINVAL); |
| 85 | if (count == 0) |
| 86 | return NULL; |
| 87 | acl = posix_acl_alloc(count, GFP_NOFS); |
| 88 | if (!acl) |
| 89 | return ERR_PTR(-ENOMEM); |
| 90 | for (n = 0; n < count; n++) { |
| 91 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; |
| 92 | if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) |
| 93 | goto fail; |
| 94 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); |
| 95 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); |
| 96 | switch (acl->a_entries[n].e_tag) { |
| 97 | case ACL_USER_OBJ: |
| 98 | case ACL_GROUP_OBJ: |
| 99 | case ACL_MASK: |
| 100 | case ACL_OTHER: |
| 101 | value = (char *)value + |
| 102 | sizeof(reiserfs_acl_entry_short); |
| 103 | break; |
| 104 | |
| 105 | case ACL_USER: |
| 106 | value = (char *)value + sizeof(reiserfs_acl_entry); |
| 107 | if ((char *)value > end) |
| 108 | goto fail; |
| 109 | acl->a_entries[n].e_uid = |
| 110 | make_kuid(&init_user_ns, |
| 111 | le32_to_cpu(entry->e_id)); |
| 112 | break; |
| 113 | case ACL_GROUP: |
| 114 | value = (char *)value + sizeof(reiserfs_acl_entry); |
| 115 | if ((char *)value > end) |
| 116 | goto fail; |
| 117 | acl->a_entries[n].e_gid = |
| 118 | make_kgid(&init_user_ns, |
| 119 | le32_to_cpu(entry->e_id)); |
| 120 | break; |
| 121 | |
| 122 | default: |
| 123 | goto fail; |
| 124 | } |
| 125 | } |
| 126 | if (value != end) |
| 127 | goto fail; |
| 128 | return acl; |
| 129 | |
| 130 | fail: |
| 131 | posix_acl_release(acl); |
| 132 | return ERR_PTR(-EINVAL); |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * Convert from in-memory to filesystem representation. |
| 137 | */ |
| 138 | static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) |
| 139 | { |
| 140 | reiserfs_acl_header *ext_acl; |
| 141 | char *e; |
| 142 | int n; |
| 143 | |
| 144 | *size = reiserfs_acl_size(acl->a_count); |
| 145 | ext_acl = kmalloc(sizeof(reiserfs_acl_header) + |
| 146 | acl->a_count * |
| 147 | sizeof(reiserfs_acl_entry), |
| 148 | GFP_NOFS); |
| 149 | if (!ext_acl) |
| 150 | return ERR_PTR(-ENOMEM); |
| 151 | ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); |
| 152 | e = (char *)ext_acl + sizeof(reiserfs_acl_header); |
| 153 | for (n = 0; n < acl->a_count; n++) { |
| 154 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; |
| 155 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; |
| 156 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); |
| 157 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); |
| 158 | switch (acl->a_entries[n].e_tag) { |
| 159 | case ACL_USER: |
| 160 | entry->e_id = cpu_to_le32( |
| 161 | from_kuid(&init_user_ns, acl_e->e_uid)); |
| 162 | e += sizeof(reiserfs_acl_entry); |
| 163 | break; |
| 164 | case ACL_GROUP: |
| 165 | entry->e_id = cpu_to_le32( |
| 166 | from_kgid(&init_user_ns, acl_e->e_gid)); |
| 167 | e += sizeof(reiserfs_acl_entry); |
| 168 | break; |
| 169 | |
| 170 | case ACL_USER_OBJ: |
| 171 | case ACL_GROUP_OBJ: |
| 172 | case ACL_MASK: |
| 173 | case ACL_OTHER: |
| 174 | e += sizeof(reiserfs_acl_entry_short); |
| 175 | break; |
| 176 | |
| 177 | default: |
| 178 | goto fail; |
| 179 | } |
| 180 | } |
| 181 | return (char *)ext_acl; |
| 182 | |
| 183 | fail: |
| 184 | kfree(ext_acl); |
| 185 | return ERR_PTR(-EINVAL); |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * Inode operation get_posix_acl(). |
| 190 | * |
| 191 | * inode->i_mutex: down |
| 192 | * BKL held [before 2.5.x] |
| 193 | */ |
| 194 | struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, bool rcu) |
| 195 | { |
| 196 | char *name, *value; |
| 197 | struct posix_acl *acl; |
| 198 | int size; |
| 199 | int retval; |
| 200 | |
| 201 | if (rcu) |
| 202 | return ERR_PTR(-ECHILD); |
| 203 | |
| 204 | switch (type) { |
| 205 | case ACL_TYPE_ACCESS: |
| 206 | name = XATTR_NAME_POSIX_ACL_ACCESS; |
| 207 | break; |
| 208 | case ACL_TYPE_DEFAULT: |
| 209 | name = XATTR_NAME_POSIX_ACL_DEFAULT; |
| 210 | break; |
| 211 | default: |
| 212 | BUG(); |
| 213 | } |
| 214 | |
| 215 | size = reiserfs_xattr_get(inode, name, NULL, 0); |
| 216 | if (size < 0) { |
| 217 | if (size == -ENODATA || size == -ENOSYS) |
| 218 | return NULL; |
| 219 | return ERR_PTR(size); |
| 220 | } |
| 221 | |
| 222 | value = kmalloc(size, GFP_NOFS); |
| 223 | if (!value) |
| 224 | return ERR_PTR(-ENOMEM); |
| 225 | |
| 226 | retval = reiserfs_xattr_get(inode, name, value, size); |
| 227 | if (retval == -ENODATA || retval == -ENOSYS) { |
| 228 | /* |
| 229 | * This shouldn't actually happen as it should have |
| 230 | * been caught above.. but just in case |
| 231 | */ |
| 232 | acl = NULL; |
| 233 | } else if (retval < 0) { |
| 234 | acl = ERR_PTR(retval); |
| 235 | } else { |
| 236 | acl = reiserfs_posix_acl_from_disk(value, retval); |
| 237 | } |
| 238 | |
| 239 | kfree(value); |
| 240 | return acl; |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * Inode operation set_posix_acl(). |
| 245 | * |
| 246 | * inode->i_mutex: down |
| 247 | * BKL held [before 2.5.x] |
| 248 | */ |
| 249 | static int |
| 250 | __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, |
| 251 | int type, struct posix_acl *acl) |
| 252 | { |
| 253 | char *name; |
| 254 | void *value = NULL; |
| 255 | size_t size = 0; |
| 256 | int error; |
| 257 | |
| 258 | switch (type) { |
| 259 | case ACL_TYPE_ACCESS: |
| 260 | name = XATTR_NAME_POSIX_ACL_ACCESS; |
| 261 | break; |
| 262 | case ACL_TYPE_DEFAULT: |
| 263 | name = XATTR_NAME_POSIX_ACL_DEFAULT; |
| 264 | if (!S_ISDIR(inode->i_mode)) |
| 265 | return acl ? -EACCES : 0; |
| 266 | break; |
| 267 | default: |
| 268 | return -EINVAL; |
| 269 | } |
| 270 | |
| 271 | if (acl) { |
| 272 | value = reiserfs_posix_acl_to_disk(acl, &size); |
| 273 | if (IS_ERR(value)) |
| 274 | return (int)PTR_ERR(value); |
| 275 | } |
| 276 | |
| 277 | error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); |
| 278 | |
| 279 | /* |
| 280 | * Ensure that the inode gets dirtied if we're only using |
| 281 | * the mode bits and an old ACL didn't exist. We don't need |
| 282 | * to check if the inode is hashed here since we won't get |
| 283 | * called by reiserfs_inherit_default_acl(). |
| 284 | */ |
| 285 | if (error == -ENODATA) { |
| 286 | error = 0; |
| 287 | if (type == ACL_TYPE_ACCESS) { |
| 288 | inode->i_ctime = current_time(inode); |
| 289 | mark_inode_dirty(inode); |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | kfree(value); |
| 294 | |
| 295 | if (!error) |
| 296 | set_cached_acl(inode, type, acl); |
| 297 | |
| 298 | return error; |
| 299 | } |
| 300 | |
| 301 | /* |
| 302 | * dir->i_mutex: locked, |
| 303 | * inode is new and not released into the wild yet |
| 304 | */ |
| 305 | int |
| 306 | reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, |
| 307 | struct inode *dir, struct dentry *dentry, |
| 308 | struct inode *inode) |
| 309 | { |
| 310 | struct posix_acl *default_acl, *acl; |
| 311 | int err = 0; |
| 312 | |
| 313 | /* ACLs only get applied to files and directories */ |
| 314 | if (S_ISLNK(inode->i_mode)) |
| 315 | return 0; |
| 316 | |
| 317 | /* |
| 318 | * ACLs can only be used on "new" objects, so if it's an old object |
| 319 | * there is nothing to inherit from |
| 320 | */ |
| 321 | if (get_inode_sd_version(dir) == STAT_DATA_V1) |
| 322 | goto apply_umask; |
| 323 | |
| 324 | /* |
| 325 | * Don't apply ACLs to objects in the .reiserfs_priv tree.. This |
| 326 | * would be useless since permissions are ignored, and a pain because |
| 327 | * it introduces locking cycles |
| 328 | */ |
| 329 | if (IS_PRIVATE(inode)) |
| 330 | goto apply_umask; |
| 331 | |
| 332 | err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); |
| 333 | if (err) |
| 334 | return err; |
| 335 | |
| 336 | if (default_acl) { |
| 337 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, |
| 338 | default_acl); |
| 339 | posix_acl_release(default_acl); |
| 340 | } |
| 341 | if (acl) { |
| 342 | if (!err) |
| 343 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, |
| 344 | acl); |
| 345 | posix_acl_release(acl); |
| 346 | } |
| 347 | |
| 348 | return err; |
| 349 | |
| 350 | apply_umask: |
| 351 | /* no ACL, apply umask */ |
| 352 | inode->i_mode &= ~current_umask(); |
| 353 | return err; |
| 354 | } |
| 355 | |
| 356 | /* This is used to cache the default acl before a new object is created. |
| 357 | * The biggest reason for this is to get an idea of how many blocks will |
| 358 | * actually be required for the create operation if we must inherit an ACL. |
| 359 | * An ACL write can add up to 3 object creations and an additional file write |
| 360 | * so we'd prefer not to reserve that many blocks in the journal if we can. |
| 361 | * It also has the advantage of not loading the ACL with a transaction open, |
| 362 | * this may seem silly, but if the owner of the directory is doing the |
| 363 | * creation, the ACL may not be loaded since the permissions wouldn't require |
| 364 | * it. |
| 365 | * We return the number of blocks required for the transaction. |
| 366 | */ |
| 367 | int reiserfs_cache_default_acl(struct inode *inode) |
| 368 | { |
| 369 | struct posix_acl *acl; |
| 370 | int nblocks = 0; |
| 371 | |
| 372 | if (IS_PRIVATE(inode)) |
| 373 | return 0; |
| 374 | |
| 375 | acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); |
| 376 | |
| 377 | if (acl && !IS_ERR(acl)) { |
| 378 | int size = reiserfs_acl_size(acl->a_count); |
| 379 | |
| 380 | /* Other xattrs can be created during inode creation. We don't |
| 381 | * want to claim too many blocks, so we check to see if we |
| 382 | * need to create the tree to the xattrs, and then we |
| 383 | * just want two files. */ |
| 384 | nblocks = reiserfs_xattr_jcreate_nblocks(inode); |
| 385 | nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); |
| 386 | |
| 387 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; |
| 388 | |
| 389 | /* We need to account for writes + bitmaps for two files */ |
| 390 | nblocks += reiserfs_xattr_nblocks(inode, size) * 4; |
| 391 | posix_acl_release(acl); |
| 392 | } |
| 393 | |
| 394 | return nblocks; |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Called under i_mutex |
| 399 | */ |
| 400 | int reiserfs_acl_chmod(struct dentry *dentry) |
| 401 | { |
| 402 | struct inode *inode = d_inode(dentry); |
| 403 | |
| 404 | if (IS_PRIVATE(inode)) |
| 405 | return 0; |
| 406 | if (get_inode_sd_version(inode) == STAT_DATA_V1 || |
| 407 | !reiserfs_posixacl(inode->i_sb)) |
| 408 | return 0; |
| 409 | |
| 410 | return posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); |
| 411 | } |