From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B5CAC4332D for ; Mon, 4 Jan 2021 16:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65D3D22473 for ; Mon, 4 Jan 2021 16:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727948AbhADP7b (ORCPT ); Mon, 4 Jan 2021 10:59:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:36552 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727747AbhADP73 (ORCPT ); Mon, 4 Jan 2021 10:59:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B13E422507; Mon, 4 Jan 2021 15:58:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609775904; bh=3BxlnZ3kTqvMMXA8AMUdXLKpvLjsfwvWm11qjPs+6P0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vQjksqZgpC7xFkqibW51RTC7Rz/U6VlNy4eDbcZVtik0hmJSiLgAIA7gNWuGYNwHc xfR3wpmJJY/OZ4CXlmzVY2XUT4rd+dPOPfeY2ZG4Bg2AtkBsC60SKBNVNe5yRMIg+h stmvvSuahZNhlWJl3DFRuQ+dEedYVajVUvUIMyXE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Eric Biggers Subject: [PATCH 4.19 05/35] ubifs: prevent creating duplicate encrypted filenames Date: Mon, 4 Jan 2021 16:57:08 +0100 Message-Id: <20210104155703.649826444@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210104155703.375788488@linuxfoundation.org> References: <20210104155703.375788488@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers commit 76786a0f083473de31678bdb259a3d4167cf756d upstream. As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to create a duplicate filename in an encrypted directory by creating a file concurrently with adding the directory's encryption key. Fix this bug on ubifs by rejecting no-key dentries in ubifs_create(), ubifs_mkdir(), ubifs_mknod(), and ubifs_symlink(). Note that ubifs doesn't actually report the duplicate filenames from readdir, but rather it seems to replace the original dentry with a new one (which is still wrong, just a different effect from ext4). On ubifs, this fixes xfstest generic/595 as well as the new xfstest I wrote specifically for this bug. Fixes: f4f61d2cc6d8 ("ubifs: Implement encrypted filenames") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201118075609.120337-5-ebiggers@kernel.org Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman --- fs/ubifs/dir.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -290,6 +290,15 @@ done: return d_splice_alias(inode, dentry); } +static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry, + struct fscrypt_name *nm) +{ + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; + + return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm); +} + static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { @@ -313,7 +322,7 @@ static int ubifs_create(struct inode *di if (err) return err; - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg; @@ -977,7 +986,7 @@ static int ubifs_mkdir(struct inode *dir if (err) return err; - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg; @@ -1062,7 +1071,7 @@ static int ubifs_mknod(struct inode *dir return err; } - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + err = ubifs_prepare_create(dir, dentry, &nm); if (err) { kfree(dev); goto out_budg; @@ -1146,7 +1155,7 @@ static int ubifs_symlink(struct inode *d if (err) return err; - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + err = ubifs_prepare_create(dir, dentry, &nm); if (err) goto out_budg;