From ca7f85be8d6cf9ad1b6597e5d907ddbe392082a9 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Sat, 8 Oct 2016 13:24:26 +0200 Subject: ubifs: Add support for encrypted symlinks Signed-off-by: Richard Weinberger --- fs/ubifs/dir.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++-------- fs/ubifs/file.c | 55 ++++++++++++++++++++++++++++++++++++- fs/ubifs/super.c | 1 - 3 files changed, 126 insertions(+), 13 deletions(-) (limited to 'fs/ubifs') diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 7d1bd4b28140..7d3bc3fb8831 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -629,7 +629,7 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx) fstr.len = fstr_real_len; err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c, &dent->key), 0, &nm.disk_name, &fstr); - if (err < 0) + if (err) goto out; } else { fstr.len = fname_len(&nm); @@ -1164,10 +1164,27 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, struct ubifs_inode *dir_ui = ubifs_inode(dir); struct ubifs_info *c = dir->i_sb->s_fs_info; int err, len = strlen(symname); - int sz_change = CALC_DENT_SIZE(dentry->d_name.len); + int sz_change = CALC_DENT_SIZE(len); + struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1); + struct fscrypt_symlink_data *sd = NULL; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, .new_ino_d = ALIGN(len, 8), .dirtied_ino = 1 }; + struct fscrypt_name nm; + + if (ubifs_crypt_is_encrypted(dir)) { + err = fscrypt_get_encryption_info(dir); + if (err) + goto out_budg; + + if (!fscrypt_has_encryption_key(dir)) { + err = -EPERM; + goto out_budg; + } + + disk_link.len = (fscrypt_fname_encrypted_size(dir, len) + + sizeof(struct fscrypt_symlink_data)); + } /* * Budget request settings: new inode, new direntry and changing parent @@ -1177,36 +1194,77 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry, symname, dir->i_ino); - if (len > UBIFS_MAX_INO_DATA) + if (disk_link.len > UBIFS_MAX_INO_DATA) return -ENAMETOOLONG; err = ubifs_budget_space(c, &req); if (err) return err; + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + goto out_budg; + inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); if (IS_ERR(inode)) { err = PTR_ERR(inode); - goto out_budg; + goto out_fname; } ui = ubifs_inode(inode); - ui->data = kmalloc(len + 1, GFP_NOFS); + ui->data = kmalloc(disk_link.len, GFP_NOFS); if (!ui->data) { err = -ENOMEM; goto out_inode; } - memcpy(ui->data, symname, len); - ((char *)ui->data)[len] = '\0'; - inode->i_link = ui->data; + if (ubifs_crypt_is_encrypted(dir)) { + struct qstr istr = QSTR_INIT(symname, len); + struct fscrypt_str ostr; + + sd = kzalloc(disk_link.len, GFP_NOFS); + if (!sd) { + err = -ENOMEM; + goto out_inode; + } + + err = fscrypt_get_encryption_info(inode); + if (err) { + kfree(sd); + goto out_inode; + } + + if (!fscrypt_has_encryption_key(inode)) { + kfree(sd); + err = -EPERM; + goto out_inode; + } + + ostr.name = sd->encrypted_path; + ostr.len = disk_link.len; + + err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr); + if (err) { + kfree(sd); + goto out_inode; + } + + sd->len = cpu_to_le16(ostr.len); + disk_link.name = (char *)sd; + } else { + inode->i_link = ui->data; + } + + memcpy(ui->data, disk_link.name, disk_link.len); + ((char *)ui->data)[disk_link.len - 1] = '\0'; + /* * The terminating zero byte is not written to the flash media and it * is put just to make later in-memory string processing simpler. Thus, * data length is @len, not @len + %1. */ - ui->data_len = len; - inode->i_size = ubifs_inode(inode)->ui_size = len; + ui->data_len = disk_link.len - 1; + inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1; err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) @@ -1216,7 +1274,7 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -1224,6 +1282,7 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, ubifs_release_budget(c, &req); insert_inode_hash(inode); d_instantiate(dentry, inode); + fscrypt_free_filename(&nm); return 0; out_cancel: @@ -1233,6 +1292,8 @@ out_cancel: out_inode: make_bad_inode(inode); iput(inode); +out_fname: + fscrypt_free_filename(&nm); out_budg: ubifs_release_budget(c, &req); return err; diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 4c50f8feb0d5..aa0625f4f642 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1657,6 +1657,59 @@ static int ubifs_file_open(struct inode *inode, struct file *filp) return 0; } +static const char *ubifs_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + int err; + struct fscrypt_symlink_data *sd; + struct ubifs_inode *ui = ubifs_inode(inode); + struct fscrypt_str cstr; + struct fscrypt_str pstr; + + if (!ubifs_crypt_is_encrypted(inode)) + return ui->data; + + if (!dentry) + return ERR_PTR(-ECHILD); + + err = fscrypt_get_encryption_info(inode); + if (err) + return ERR_PTR(err); + + sd = (struct fscrypt_symlink_data *)ui->data; + cstr.name = sd->encrypted_path; + cstr.len = le16_to_cpu(sd->len); + + if (cstr.len == 0) + return ERR_PTR(-ENOENT); + + if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > ui->data_len) + return ERR_PTR(-EIO); + + err = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr); + if (err) + return ERR_PTR(err); + + err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr); + if (err) { + fscrypt_fname_free_buffer(&pstr); + return ERR_PTR(err); + } + + pstr.name[pstr.len] = '\0'; + + // XXX this probably won't happen anymore... + if (pstr.name[0] == '\0') { + fscrypt_fname_free_buffer(&pstr); + return ERR_PTR(-ENOENT); + } + + set_delayed_call(done, kfree_link, pstr.name); + return pstr.name; +} + + const struct address_space_operations ubifs_file_address_operations = { .readpage = ubifs_readpage, .writepage = ubifs_writepage, @@ -1681,7 +1734,7 @@ const struct inode_operations ubifs_file_inode_operations = { const struct inode_operations ubifs_symlink_inode_operations = { .readlink = generic_readlink, - .get_link = simple_get_link, + .get_link = ubifs_get_link, .setattr = ubifs_setattr, .getattr = ubifs_getattr, .listxattr = ubifs_listxattr, diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index ae25c908fbe5..e08aa04fc835 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -198,7 +198,6 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum) } memcpy(ui->data, ino->data, ui->data_len); ((char *)ui->data)[ui->data_len] = '\0'; - inode->i_link = ui->data; break; case S_IFBLK: case S_IFCHR: -- cgit v1.2.3-59-g8ed1b