From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755972AbdEESgz (ORCPT ); Fri, 5 May 2017 14:36:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59132 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755040AbdEESeX (ORCPT ); Fri, 5 May 2017 14:34:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro , Theodore Tso , Eric Biggers Subject: [PATCH 4.4 17/20] ext4 crypto: use dget_parent() in ext4_d_revalidate() Date: Fri, 5 May 2017 11:33:07 -0700 Message-Id: <20170505183231.608205479@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170505183230.937615081@linuxfoundation.org> References: <20170505183230.937615081@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 3d43bcfef5f0548845a425365011c499875491b0 upstream. This avoids potential problems caused by a race where the inode gets renamed out from its parent directory and the parent directory is deleted while ext4_d_revalidate() is running. Fixes: 28b4c263961c Reported-by: Al Viro Signed-off-by: Theodore Ts'o Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman --- fs/ext4/crypto.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -477,16 +477,21 @@ uint32_t ext4_validate_encryption_key_si */ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) { - struct inode *dir = d_inode(dentry->d_parent); - struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info; + struct dentry *dir; + struct ext4_crypt_info *ci; int dir_has_key, cached_with_key; - if (!ext4_encrypted_inode(dir)) + dir = dget_parent(dentry); + if (!ext4_encrypted_inode(d_inode(dir))) { + dput(dir); return 0; + } + ci = EXT4_I(d_inode(dir))->i_crypt_info; /* this should eventually be an flag in d_flags */ cached_with_key = dentry->d_fsdata != NULL; dir_has_key = (ci != NULL); + dput(dir); /* * If the dentry was cached without the key, and it is a