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,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 DE44FC433E0 for ; Tue, 5 Jan 2021 09:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89AF720756 for ; Tue, 5 Jan 2021 09:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725822AbhAEJbO (ORCPT ); Tue, 5 Jan 2021 04:31:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:49238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725803AbhAEJ3d (ORCPT ); Tue, 5 Jan 2021 04:29:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C0E6122AAA; Tue, 5 Jan 2021 09:28:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609838920; bh=rJIdyn+V37VsNc15Ud6KcMHR9dHN03RWxAoL3TdeyFc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VGporJdbpBuqQGDwhHDSWiF0ZEwdESpPytWSkEfwBFVIjaHW6RRz4+rD583jmtk2P k0fsQXw5fmB8cFpkQLfx8dbSIITC+PxN4VQ/6eEMlv4WitK24JPingYmFflc6Kkklj 8dJEm7WQqTcNEEvxpjukNItIhaam10Hsvs/zr5dA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Eric Biggers Subject: [PATCH 4.19 04/29] f2fs: prevent creating duplicate encrypted filenames Date: Tue, 5 Jan 2021 10:28:50 +0100 Message-Id: <20210105090819.061975458@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210105090818.518271884@linuxfoundation.org> References: <20210105090818.518271884@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 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 Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/f2fs.h | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2857,6 +2857,8 @@ 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); }