From patchwork Wed Nov 11 21:34:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 11898557 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 43D44921 for ; Wed, 11 Nov 2020 21:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BC682100A for ; Wed, 11 Nov 2020 21:34:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727145AbgKKVev (ORCPT ); Wed, 11 Nov 2020 16:34:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727097AbgKKVev (ORCPT ); Wed, 11 Nov 2020 16:34:51 -0500 Received: from smtp-bc0c.mail.infomaniak.ch (smtp-bc0c.mail.infomaniak.ch [IPv6:2001:1600:4:17::bc0c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2C15C0613D4 for ; Wed, 11 Nov 2020 13:34:50 -0800 (PST) Received: from smtp-2-0001.mail.infomaniak.ch (unknown [10.5.36.108]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4CWdKz2lNrzlhbQT; Wed, 11 Nov 2020 22:34:47 +0100 (CET) Received: from localhost (unknown [94.23.54.103]) by smtp-2-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4CWdKz0tvLzlh8TF; Wed, 11 Nov 2020 22:34:47 +0100 (CET) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: James Morris , Jann Horn , "Serge E . Hallyn" Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Shuah Khan , Vincent Dagonneau , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v1 2/9] landlock: Cosmetic fixes for filesystem management Date: Wed, 11 Nov 2020 22:34:35 +0100 Message-Id: <20201111213442.434639-3-mic@digikod.net> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201111213442.434639-1-mic@digikod.net> References: <20201111213442.434639-1-mic@digikod.net> MIME-Version: 1.0 Precedence: bulk List-ID: Improve comments and make get_inode_object() more readable. The kfree() call is correct but we should mimimize as much as possible lock windows. Cc: James Morris Cc: Jann Horn Cc: Serge E. Hallyn Signed-off-by: Mickaël Salaün Reviewed-by: James Morris --- security/landlock/fs.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/security/landlock/fs.c b/security/landlock/fs.c index b67c821bb40b..33fc7ae17c7f 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -85,8 +85,8 @@ static struct landlock_object *get_inode_object(struct inode *const inode) return object; } /* - * We're racing with release_inode(), the object is going away. - * Wait for release_inode(), then retry. + * We are racing with release_inode(), the object is going + * away. Wait for release_inode(), then retry. */ spin_lock(&object->lock); spin_unlock(&object->lock); @@ -107,21 +107,21 @@ static struct landlock_object *get_inode_object(struct inode *const inode) lockdep_is_held(&inode->i_lock)); if (unlikely(object)) { /* Someone else just created the object, bail out and retry. */ - kfree(new_object); spin_unlock(&inode->i_lock); + kfree(new_object); rcu_read_lock(); goto retry; - } else { - rcu_assign_pointer(inode_sec->object, new_object); - /* - * @inode will be released by hook_sb_delete() on its - * superblock shutdown. - */ - ihold(inode); - spin_unlock(&inode->i_lock); - return new_object; } + + rcu_assign_pointer(inode_sec->object, new_object); + /* + * @inode will be released by hook_sb_delete() on its superblock + * shutdown. + */ + ihold(inode); + spin_unlock(&inode->i_lock); + return new_object; } /* All access rights which can be tied to files. */