From patchwork Wed Jun 19 13:19:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11004149 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A00CD14B6 for ; Wed, 19 Jun 2019 13:19:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8DA2626E1A for ; Wed, 19 Jun 2019 13:19:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8100C283BB; Wed, 19 Jun 2019 13:19:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1C6CC283A2 for ; Wed, 19 Jun 2019 13:19:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727069AbfFSNT2 (ORCPT ); Wed, 19 Jun 2019 09:19:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36626 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726518AbfFSNT2 (ORCPT ); Wed, 19 Jun 2019 09:19:28 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AE5A61796; Wed, 19 Jun 2019 13:19:27 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-57.rdu2.redhat.com [10.10.120.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 956615D71A; Wed, 19 Jun 2019 13:19:24 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 05/10] keys: Break bits out of key_unlink() [ver #3] From: David Howells To: keyrings@vger.kernel.org, ebiggers@kernel.org Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 19 Jun 2019 14:19:23 +0100 Message-ID: <156095036385.9363.921620306060848348.stgit@warthog.procyon.org.uk> In-Reply-To: <156095032052.9363.8954337545422131435.stgit@warthog.procyon.org.uk> References: <156095032052.9363.8954337545422131435.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 19 Jun 2019 13:19:27 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Break bits out of key_unlink() into helper functions so that they can be used in implementing key_move(). Signed-off-by: David Howells --- security/keys/keyring.c | 88 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 67 insertions(+), 21 deletions(-) diff --git a/security/keys/keyring.c b/security/keys/keyring.c index ca6694ba1773..6990c7761eaa 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1382,6 +1382,65 @@ int key_link(struct key *keyring, struct key *key) } EXPORT_SYMBOL(key_link); +/* + * Lock a keyring for unlink. + */ +static int __key_unlink_lock(struct key *keyring) + __acquires(&keyring->sem) +{ + if (keyring->type != &key_type_keyring) + return -ENOTDIR; + + down_write(&keyring->sem); + return 0; +} + +/* + * Begin the process of unlinking a key from a keyring. + */ +static int __key_unlink_begin(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) +{ + struct assoc_array_edit *edit; + + BUG_ON(*_edit != NULL); + + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, + &key->index_key); + if (IS_ERR(edit)) + return PTR_ERR(edit); + + if (!edit) + return -ENOENT; + + *_edit = edit; + return 0; +} + +/* + * Apply an unlink change. + */ +static void __key_unlink(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) +{ + assoc_array_apply_edit(*_edit); + *_edit = NULL; + key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); +} + +/* + * Finish unlinking a key from to a keyring. + */ +static void __key_unlink_end(struct key *keyring, + struct key *key, + struct assoc_array_edit *edit) + __releases(&keyring->sem) +{ + if (edit) + assoc_array_cancel_edit(edit); + up_write(&keyring->sem); +} + /** * key_unlink - Unlink the first link to a key from a keyring. * @keyring: The keyring to remove the link from. @@ -1401,33 +1460,20 @@ EXPORT_SYMBOL(key_link); */ int key_unlink(struct key *keyring, struct key *key) { - struct assoc_array_edit *edit; + struct assoc_array_edit *edit = NULL; int ret; key_check(keyring); key_check(key); - if (keyring->type != &key_type_keyring) - return -ENOTDIR; - - down_write(&keyring->sem); - - edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, - &key->index_key); - if (IS_ERR(edit)) { - ret = PTR_ERR(edit); - goto error; - } - ret = -ENOENT; - if (edit == NULL) - goto error; - - assoc_array_apply_edit(edit); - key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); - ret = 0; + ret = __key_unlink_lock(keyring); + if (ret < 0) + return ret; -error: - up_write(&keyring->sem); + ret = __key_unlink_begin(keyring, key, &edit); + if (ret == 0) + __key_unlink(keyring, key, &edit); + __key_unlink_end(keyring, key, edit); return ret; } EXPORT_SYMBOL(key_unlink);