From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758292AbaCTMhk (ORCPT ); Thu, 20 Mar 2014 08:37:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29762 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757281AbaCTMhf (ORCPT ); Thu, 20 Mar 2014 08:37:35 -0400 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 10/12] KEYS: big_key: Use key preparsing From: David Howells To: keyrings@linux-nfs.org Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 20 Mar 2014 12:05:49 +0000 Message-ID: <20140320120549.21635.97439.stgit@warthog.procyon.org.uk> In-Reply-To: <20140320120428.21635.13071.stgit@warthog.procyon.org.uk> References: <20140320120428.21635.13071.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make use of key preparsing in the big key type so that quota size determination can take place prior to keyring locking when a key is being added. Signed-off-by: David Howells --- include/keys/big_key-type.h | 3 ++- security/keys/big_key.c | 41 +++++++++++++++++++++++++---------------- 2 files changed, 27 insertions(+), 17 deletions(-) diff --git a/include/keys/big_key-type.h b/include/keys/big_key-type.h index d69bc8af3292..e0970a578188 100644 --- a/include/keys/big_key-type.h +++ b/include/keys/big_key-type.h @@ -16,7 +16,8 @@ extern struct key_type key_type_big_key; -extern int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep); +extern int big_key_preparse(struct key_preparsed_payload *prep); +extern void big_key_free_preparse(struct key_preparsed_payload *prep); extern void big_key_revoke(struct key *key); extern void big_key_destroy(struct key *key); extern void big_key_describe(const struct key *big_key, struct seq_file *m); diff --git a/security/keys/big_key.c b/security/keys/big_key.c index 8137b27d641d..c2f91a0cf889 100644 --- a/security/keys/big_key.c +++ b/security/keys/big_key.c @@ -34,7 +34,9 @@ MODULE_LICENSE("GPL"); struct key_type key_type_big_key = { .name = "big_key", .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, - .instantiate = big_key_instantiate, + .preparse = big_key_preparse, + .free_preparse = big_key_free_preparse, + .instantiate = generic_key_instantiate, .match = user_match, .revoke = big_key_revoke, .destroy = big_key_destroy, @@ -43,11 +45,11 @@ struct key_type key_type_big_key = { }; /* - * Instantiate a big key + * Preparse a big key */ -int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +int big_key_preparse(struct key_preparsed_payload *prep) { - struct path *path = (struct path *)&key->payload.data2; + struct path *path = (struct path *)&prep->payload; struct file *file; ssize_t written; size_t datalen = prep->datalen; @@ -58,11 +60,9 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) goto error; /* Set an arbitrary quota */ - ret = key_payload_reserve(key, 16); - if (ret < 0) - goto error; + prep->quotalen = 16; - key->type_data.x[1] = datalen; + prep->type_data[1] = (void *)(unsigned long)datalen; if (datalen > BIG_KEY_FILE_THRESHOLD) { /* Create a shmem file to store the data in. This will permit the data @@ -73,7 +73,7 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) file = shmem_kernel_file_setup("", datalen, 0); if (IS_ERR(file)) { ret = PTR_ERR(file); - goto err_quota; + goto error; } written = kernel_write(file, prep->data, prep->datalen, 0); @@ -93,24 +93,33 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) } else { /* Just store the data in a buffer */ void *data = kmalloc(datalen, GFP_KERNEL); - if (!data) { - ret = -ENOMEM; - goto err_quota; - } + if (!data) + return -ENOMEM; - key->payload.data = memcpy(data, prep->data, prep->datalen); + prep->payload[0] = memcpy(data, prep->data, prep->datalen); } return 0; err_fput: fput(file); -err_quota: - key_payload_reserve(key, 0); error: return ret; } /* + * Clear preparsement. + */ +void big_key_free_preparse(struct key_preparsed_payload *prep) +{ + if (prep->datalen > BIG_KEY_FILE_THRESHOLD) { + struct path *path = (struct path *)&prep->payload; + path_put(path); + } else { + kfree(prep->payload[0]); + } +} + +/* * dispose of the links from a revoked keyring * - called with the key sem write-locked */