Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933978AbcJUMz0 (ORCPT ); Fri, 21 Oct 2016 08:55:26 -0400 Received: from mail.sigma-star.at ([95.130.255.111]:46010 "EHLO mail.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932876AbcJUMtW (ORCPT ); Fri, 21 Oct 2016 08:49:22 -0400 From: Richard Weinberger To: linux-mtd@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, dedekind1@gmail.com, adrian.hunter@intel.com, tytso@mit.edu, jaegeuk@kernel.org, david@sigma-star.at, wd@denx.de, sbabic@denx.de, dengler@linutronix.de, Richard Weinberger Subject: [PATCH 20/26] ubifs: Add support for encrypted symlinks Date: Fri, 21 Oct 2016 14:48:35 +0200 Message-Id: <1477054121-10198-21-git-send-email-richard@nod.at> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1477054121-10198-1-git-send-email-richard@nod.at> References: <1477054121-10198-1-git-send-email-richard@nod.at> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6637 Lines: 239 Signed-off-by: Richard Weinberger --- fs/ubifs/dir.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++------- fs/ubifs/file.c | 55 +++++++++++++++++++++++++++++++++++++- fs/ubifs/super.c | 1 - 3 files changed, 125 insertions(+), 12 deletions(-) diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 723bae4dec30..2f33be5ca57c 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1051,10 +1051,27 @@ 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 @@ -1064,36 +1081,77 @@ 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 < 0) { + 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) @@ -1103,7 +1161,7 @@ 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); @@ -1111,6 +1169,7 @@ 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: @@ -1120,6 +1179,8 @@ 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 60e089d50c82..ce168b3f61ca 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1679,6 +1679,59 @@ 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 (!dentry) + return ERR_PTR(-ECHILD); + + if (ubifs_crypt_is_encrypted(inode)) { + err = fscrypt_get_encryption_info(inode); + if (err) + return ERR_PTR(err); + } else + return ui->data; + + + 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 < 0) { + fscrypt_fname_free_buffer(&pstr); + return ERR_PTR(err); + } + + pstr.name[err] = '\0'; + + 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, @@ -1706,7 +1759,7 @@ 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, .setxattr = generic_setxattr, 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: -- 2.7.3