From patchwork Mon Dec 28 18:54:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 352932 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=-19.2 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 61648C433DB for ; Mon, 28 Dec 2020 18:56:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22E94221F8 for ; Mon, 28 Dec 2020 18:56:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728872AbgL1S4M (ORCPT ); Mon, 28 Dec 2020 13:56:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:39502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728860AbgL1S4J (ORCPT ); Mon, 28 Dec 2020 13:56:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2F5EB22AEC; Mon, 28 Dec 2020 18:55:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609181729; bh=JPIVqHrwI805Fv5QGEULkWZfbaFWNrc2Kf/PlJACkgs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cddWmyMiZ4aPntME6wgF00kFSRnc4Boim1a/D5McIpUMOPhDHlUNixCFYwj7SccGs aA6jl1htDWjzpUBq8+iLhI9LRtasDJzn7z1Lh4yF9gxwdbhh23EL4YVmsJ1qbFqH3W l7lPIodxkWeCG+5xgjBKnaC/wMS40gDPqZGoNPfjWX9R0sgE2jBlszZkGW92ImTnqK N7tDK81f6dUSxh5yOK/pqgrFUCL6rzpYa14C9xm9nQ4n3tKR0BhBvrqCIQCDhREY5G e9/qXmxcsKLxkzR3Ms5unhxmJVjhQ84aFRHiJdkk1ZPDkTrsbYpuDJhSmmHsCY2HQR NescGr006WjoQ== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org Subject: [PATCH 5.4 3/4] f2fs: prevent creating duplicate encrypted filenames Date: Mon, 28 Dec 2020 10:54:32 -0800 Message-Id: <20201228185433.61129-4-ebiggers@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228185433.61129-1-ebiggers@kernel.org> References: <20201228185433.61129-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit bfc2b7e8518999003a61f91c1deb5e88ed77b07d 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 f2fs by rejecting no-key dentries in f2fs_add_link(). Note that the weird check for the current task in f2fs_do_add_link() seems to make this bug difficult to reproduce on f2fs. Fixes: 9ea97163c6da ("f2fs crypto: add filename encryption for f2fs_add_link") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201118075609.120337-4-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/f2fs/f2fs.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 63440abe58c42..0ddc4a74b9d43 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2998,6 +2998,8 @@ bool f2fs_empty_dir(struct inode *dir); static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode) { + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; return f2fs_do_add_link(d_inode(dentry->d_parent), &dentry->d_name, inode, inode->i_ino, inode->i_mode); }