From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942334AbcJZNLR (ORCPT ); Wed, 26 Oct 2016 09:11:17 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55509 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941807AbcJZM3s (ORCPT ); Wed, 26 Oct 2016 08:29:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Theodore Tso , Richard Weinberger Subject: [PATCH 4.8 131/140] fscrypto: lock inode while setting encryption policy Date: Wed, 26 Oct 2016 14:23:11 +0200 Message-Id: <20161026122226.071008285@linuxfoundation.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161026122220.384323763@linuxfoundation.org> References: <20161026122220.384323763@linuxfoundation.org> User-Agent: quilt/0.64 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 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 8906a8223ad4909b391c5628f7991ebceda30e52 upstream. i_rwsem needs to be acquired while setting an encryption policy so that concurrent calls to FS_IOC_SET_ENCRYPTION_POLICY are correctly serialized (especially the ->get_context() + ->set_context() pair), and so that new files cannot be created in the directory during or after the ->empty_dir() check. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o Reviewed-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/crypto/policy.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -109,6 +109,8 @@ int fscrypt_process_policy(struct file * if (ret) return ret; + inode_lock(inode); + if (!inode_has_encryption_context(inode)) { if (!S_ISDIR(inode->i_mode)) ret = -EINVAL; @@ -127,6 +129,8 @@ int fscrypt_process_policy(struct file * ret = -EINVAL; } + inode_unlock(inode); + mnt_drop_write_file(filp); return ret; }