From patchwork Wed Nov 18 07:56:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11914033 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 6DC56C64E7A for ; Wed, 18 Nov 2020 07:57:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E3A3246AE for ; Wed, 18 Nov 2020 07:57:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="wciZgUxR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727233AbgKRH5n (ORCPT ); Wed, 18 Nov 2020 02:57:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:35650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727179AbgKRH5l (ORCPT ); Wed, 18 Nov 2020 02:57:41 -0500 Received: from sol.attlocal.net (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 01736246B3; Wed, 18 Nov 2020 07:57:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605686261; bh=D+Kyjii18F0waqpkVXSX3zdRISdLOoxWag/Zq/plDfg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wciZgUxRsT4BpUHM/xK7x+itYlwScHX5JDV4LPcCZe9NsPUlgYTrKiN3zfYXLus8i zSemoz4gBJxKD8n9MO4HB9NPQsGOvh+QR8JnCfwKXnzA/JeCOdF3AUjT4gsXrv0t/I UpASd0HyCEVENL+ByuFX13YPNCschjAJ91tiyRiw= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 4/5] ubifs: prevent creating duplicate encrypted filenames Date: Tue, 17 Nov 2020 23:56:08 -0800 Message-Id: <20201118075609.120337-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201118075609.120337-1-ebiggers@kernel.org> References: <20201118075609.120337-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Eric Biggers 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 Signed-off-by: Eric Biggers --- fs/ubifs/dir.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 155521e51ac5..08fde777c324 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -270,6 +270,15 @@ static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry, 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) { @@ -293,7 +302,7 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, 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; @@ -953,7 +962,7 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 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; @@ -1038,7 +1047,7 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, 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; @@ -1122,7 +1131,7 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, 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;