// SPDX-License-Identifier: GPL-2.0 #include <linux/capability.h> #include <linux/fs.h> #include <linux/posix_acl.h> #include "reiserfs.h" #include <linux/errno.h> #include <linux/pagemap.h> #include <linux/xattr.h> #include <linux/slab.h> #include <linux/posix_acl_xattr.h> #include "xattr.h" #include "acl.h" #include <linux/uaccess.h> static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, int type, struct posix_acl *acl); int reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, struct posix_acl *acl, int type) { int error, error2; struct reiserfs_transaction_handle th; size_t jcreate_blocks; int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; int update_mode = 0; struct inode *inode = d_inode(dentry); umode_t mode = inode->i_mode; /* * Pessimism: We can't assume that anything from the xattr root up * has been created. */ jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + reiserfs_xattr_nblocks(inode, size) * 2; reiserfs_write_lock(inode->i_sb); error = journal_begin(&th, inode->i_sb, jcreate_blocks); reiserfs_write_unlock(inode->i_sb); if (error == 0) { if (type == ACL_TYPE_ACCESS && acl) { error = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl); if (error) goto unlock; update_mode = 1; } error = __reiserfs_set_acl(&th, inode, type, acl); if (!error && update_mode) inode->i_mode = mode; unlock: reiserfs_write_lock(inode->i_sb); error2 = journal_end(&th); reiserfs_write_unlock(inode->i_sb); if (error2) error = error2; } return error; } /* * Convert from filesystem to in-memory representation. */ static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) { const char *end = (char *)value + size; int n, count; struct posix_acl *acl; if (!value) return NULL; if (size < sizeof(reiserfs_acl_header)) return ERR_PTR(-EINVAL); if (((reiserfs_acl_header *) value)->a_version != cpu_to_le32(REISERFS_ACL_VERSION)) return ERR_PTR(-EINVAL); value = (char *)value + sizeof(reiserfs_acl_header); count = reiserfs_acl_count(size); if (count < 0) return ERR_PTR(-EINVAL); if (count == 0) return NULL; acl = posix_acl_alloc(count, GFP_NOFS); if (!acl) return ERR_PTR(-ENOMEM); for (n = 0; n < count; n++) { reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) goto fail; acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: value = (char *)value + sizeof(reiserfs_acl_entry_short); break; case ACL_USER: value = (char *)value + sizeof(reiserfs_acl_entry); if ((char *)value > end) goto fail; acl->a_entries[n].e_uid = make_kuid(&init_user_ns, le32_to_cpu(entry->e_id)); break; case ACL_GROUP: value = (char *)value + sizeof(reiserfs_acl_entry); if ((char *)value > end) goto fail; acl->a_entries[n].e_gid = make_kgid(&init_user_ns, le32_to_cpu(entry->e_id)); break; default: goto fail; } } if (value != end) goto fail; return acl; fail: posix_acl_release(acl); return ERR_PTR(-EINVAL); } /* * Convert from in-memory to filesystem representation. */ static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) { reiserfs_acl_header *ext_acl; char *e; int n; *size = reiserfs_acl_size(acl->a_count); ext_acl = kmalloc(sizeof(reiserfs_acl_header) + acl->a_count * sizeof(reiserfs_acl_entry), GFP_NOFS); if (!ext_acl) return ERR_PTR(-ENOMEM); ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); e = (char *)ext_acl + sizeof(reiserfs_acl_header); for (n = 0; n < acl->a_count; n++) { const struct posix_acl_entry *acl_e = &acl->a_entries[n]; reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER: entry->e_id = cpu_to_le32( from_kuid(&init_user_ns, acl_e->e_uid)); e += sizeof(reiserfs_acl_entry); break; case ACL_GROUP: entry->e_id = cpu_to_le32( from_kgid(&init_user_ns, acl_e->e_gid)); e += sizeof(reiserfs_acl_entry); break; case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: e += sizeof(reiserfs_acl_entry_short); break; default: goto fail; } } return (char *)ext_acl; fail: kfree(ext_acl); return ERR_PTR(-EINVAL); } /* * Inode operation get_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, bool rcu) { char *name, *value; struct posix_acl *acl; int size; int retval; if (rcu) return ERR_PTR(-ECHILD); switch (type) { case ACL_TYPE_ACCESS: name = XATTR_NAME_POSIX_ACL_ACCESS; break; case ACL_TYPE_DEFAULT: name = XATTR_NAME_POSIX_ACL_DEFAULT; break; default: BUG(); } size = reiserfs_xattr_get(inode, name, NULL, 0); if (size < 0) { if (size == -ENODATA || size == -ENOSYS) return NULL; return ERR_PTR(size); } value = kmalloc(size, GFP_NOFS); if (!value) return ERR_PTR(-ENOMEM); retval = reiserfs_xattr_get(inode, name, value, size); if (retval == -ENODATA || retval == -ENOSYS) { /* * This shouldn't actually happen as it should have * been caught above.. but just in case */ acl = NULL; } else if (retval < 0) { acl = ERR_PTR(retval); } else { acl = reiserfs_posix_acl_from_disk(value, retval); } kfree(value); return acl; } /* * Inode operation set_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, int type, struct posix_acl *acl) { char *name; void *value = NULL; size_t size = 0; int error; switch (type) { case ACL_TYPE_ACCESS: name = XATTR_NAME_POSIX_ACL_ACCESS; break; case ACL_TYPE_DEFAULT: name = XATTR_NAME_POSIX_ACL_DEFAULT; if (!S_ISDIR(inode->i_mode)) return acl ? -EACCES : 0; break; default: return -EINVAL; } if (acl) { value = reiserfs_posix_acl_to_disk(acl, &size); if (IS_ERR(value)) return (int)PTR_ERR(value); } error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); /* * Ensure that the inode gets dirtied if we're only using * the mode bits and an old ACL didn't exist. We don't need * to check if the inode is hashed here since we won't get * called by reiserfs_inherit_default_acl(). */ if (error == -ENODATA) { error = 0; if (type == ACL_TYPE_ACCESS) { inode_set_ctime_current(inode); mark_inode_dirty(inode); } } kfree(value); if (!error) set_cached_acl(inode, type, acl); return error; } /* * dir->i_mutex: locked, * inode is new and not released into the wild yet */ int reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, struct inode *dir, struct dentry *dentry, struct inode *inode) { struct posix_acl *default_acl, *acl; int err = 0; /* ACLs only get applied to files and directories */ if (S_ISLNK(inode->i_mode)) return 0; /* * ACLs can only be used on "new" objects, so if it's an old object * there is nothing to inherit from */ if (get_inode_sd_version(dir) == STAT_DATA_V1) goto apply_umask; /* * Don't apply ACLs to objects in the .reiserfs_priv tree.. This * would be useless since permissions are ignored, and a pain because * it introduces locking cycles */ if (IS_PRIVATE(inode)) goto apply_umask; err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); if (err) return err; if (default_acl) { err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, default_acl); posix_acl_release(default_acl); } if (acl) { if (!err) err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl); posix_acl_release(acl); } return err; apply_umask: /* no ACL, apply umask */ inode->i_mode &= ~current_umask(); return err; } /* This is used to cache the default acl before a new object is created. * The biggest reason for this is to get an idea of how many blocks will * actually be required for the create operation if we must inherit an ACL. * An ACL write can add up to 3 object creations and an additional file write * so we'd prefer not to reserve that many blocks in the journal if we can. * It also has the advantage of not loading the ACL with a transaction open, * this may seem silly, but if the owner of the directory is doing the * creation, the ACL may not be loaded since the permissions wouldn't require * it. * We return the number of blocks required for the transaction. */ int reiserfs_cache_default_acl(struct inode *inode) { struct posix_acl *acl; int nblocks = 0; if (IS_PRIVATE(inode)) return 0; acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); if (acl && !IS_ERR(acl)) { int size = reiserfs_acl_size(acl->a_count); /* Other xattrs can be created during inode creation. We don't * want to claim too many blocks, so we check to see if we * need to create the tree to the xattrs, and then we * just want two files. */ nblocks = reiserfs_xattr_jcreate_nblocks(inode); nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); REISERFS_I(inode)->i_flags |= i_has_xattr_dir; /* We need to account for writes + bitmaps for two files */ nblocks += reiserfs_xattr_nblocks(inode, size) * 4; posix_acl_release(acl); } return nblocks; } /* * Called under i_mutex */ int reiserfs_acl_chmod(struct dentry *dentry) { struct inode *inode = d_inode(dentry); if (IS_PRIVATE(inode)) return 0; if (get_inode_sd_version(inode) == STAT_DATA_V1 || !reiserfs_posixacl(inode->i_sb)) return 0; return posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); }