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=-18.7 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=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 84207C43217 for ; Wed, 23 Dec 2020 15:34:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D2DB23340 for ; Wed, 23 Dec 2020 15:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728887AbgLWPec (ORCPT ); Wed, 23 Dec 2020 10:34:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:44556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728818AbgLWPe0 (ORCPT ); Wed, 23 Dec 2020 10:34:26 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3AED2233F7; Wed, 23 Dec 2020 15:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1608737631; bh=ZyCbydFM64gMJFzdlQSzeKmBDvTF6zSW9cM0ftoxS0Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zcsym24qdv75r0iZLpcQndEzY/3y2n4yDHTq1Cs2HkWnozsuZNsl6qFc/z9W8PJ8U KiA7ow9m/pwrXW/8UCJEuAsKCe/VybX4PYIfwzG9rMaSjJ0yEnfjVxTOXxo/z7FN5a koyaNB48g6/+vGiw+lQq14UpeXQEKMh4/ADZOvGw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers Subject: [PATCH 5.10 32/40] ext4: prevent creating duplicate encrypted filenames Date: Wed, 23 Dec 2020 16:33:33 +0100 Message-Id: <20201223150517.084127853@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201223150515.553836647@linuxfoundation.org> References: <20201223150515.553836647@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 75d18cd1868c2aee43553723872c35d7908f240f 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 ext4 by rejecting no-key dentries in ext4_add_entry(). Note that the duplicate check in ext4_find_dest_de() sometimes prevented this bug. However in many cases it didn't, since ext4_find_dest_de() doesn't examine every dentry. Fixes: 4461471107b7 ("ext4 crypto: enable filename encryption") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201118075609.120337-3-ebiggers@kernel.org Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman --- fs/ext4/namei.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2195,6 +2195,9 @@ static int ext4_add_entry(handle_t *hand if (!dentry->d_name.len) return -EINVAL; + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; + #ifdef CONFIG_UNICODE if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))