From patchwork Wed Sep 15 09:20:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12495817 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 83CEBC433FE for ; Wed, 15 Sep 2021 09:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C0FC61246 for ; Wed, 15 Sep 2021 09:10:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237194AbhIOJLm (ORCPT ); Wed, 15 Sep 2021 05:11:42 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:19983 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237174AbhIOJLk (ORCPT ); Wed, 15 Sep 2021 05:11:40 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4H8Z864ccYzbkQ5; Wed, 15 Sep 2021 17:06:14 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Wed, 15 Sep 2021 17:10:20 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Wed, 15 Sep 2021 17:10:20 +0800 From: Yu Kuai To: , , , CC: , , , , Subject: [PATCH v7 5/6] nbd: partition nbd_read_stat() into nbd_read_reply() and nbd_handle_reply() Date: Wed, 15 Sep 2021 17:20:09 +0800 Message-ID: <20210915092010.2087371-6-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210915092010.2087371-1-yukuai3@huawei.com> References: <20210915092010.2087371-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Prepare to fix uaf in nbd_read_stat(), no functional changes. Signed-off-by: Yu Kuai --- drivers/block/nbd.c | 76 +++++++++++++++++++++++++++------------------ 1 file changed, 45 insertions(+), 31 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 22c91d8901f6..9a7bbf8ebe74 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -694,38 +694,45 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) return 0; } -/* NULL returned = something went wrong, inform userspace */ -static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) +static int nbd_read_reply(struct nbd_device *nbd, int index, + struct nbd_reply *reply) { - struct nbd_config *config = nbd->config; - int result; - struct nbd_reply reply; - struct nbd_cmd *cmd; - struct request *req = NULL; - u64 handle; - u16 hwq; - u32 tag; - struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)}; + struct kvec iov = {.iov_base = reply, .iov_len = sizeof(*reply)}; struct iov_iter to; - int ret = 0; + int result; - reply.magic = 0; - iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply)); + reply->magic = 0; + iov_iter_kvec(&to, READ, &iov, 1, sizeof(*reply)); result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL); - if (result <= 0) { - if (!nbd_disconnected(config)) + if (result < 0) { + if (!nbd_disconnected(nbd->config)) dev_err(disk_to_dev(nbd->disk), "Receive control failed (result %d)\n", result); - return ERR_PTR(result); + return result; } - if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { + if (ntohl(reply->magic) != NBD_REPLY_MAGIC) { dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", - (unsigned long)ntohl(reply.magic)); - return ERR_PTR(-EPROTO); + (unsigned long)ntohl(reply->magic)); + return -EPROTO; } - memcpy(&handle, reply.handle, sizeof(handle)); + return 0; +} + +/* NULL returned = something went wrong, inform userspace */ +static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index, + struct nbd_reply *reply) +{ + int result; + struct nbd_cmd *cmd; + struct request *req = NULL; + u64 handle; + u16 hwq; + u32 tag; + int ret = 0; + + memcpy(&handle, reply->handle, sizeof(handle)); tag = nbd_handle_to_tag(handle); hwq = blk_mq_unique_tag_to_hwq(tag); if (hwq < nbd->tag_set.nr_hw_queues) @@ -768,9 +775,9 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) ret = -ENOENT; goto out; } - if (ntohl(reply.error)) { + if (ntohl(reply->error)) { dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", - ntohl(reply.error)); + ntohl(reply->error)); cmd->status = BLK_STS_IOERR; goto out; } @@ -779,6 +786,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) if (rq_data_dir(req) != WRITE) { struct req_iterator iter; struct bio_vec bvec; + struct iov_iter to; rq_for_each_segment(bvec, req, iter) { iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len); @@ -792,7 +800,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) * and let the timeout stuff handle resubmitting * this request onto another connection. */ - if (nbd_disconnected(config)) { + if (nbd_disconnected(nbd->config)) { cmd->status = BLK_STS_IOERR; goto out; } @@ -816,24 +824,30 @@ static void recv_work(struct work_struct *work) work); struct nbd_device *nbd = args->nbd; struct nbd_config *config = nbd->config; + struct nbd_sock *nsock; struct nbd_cmd *cmd; struct request *rq; while (1) { - cmd = nbd_read_stat(nbd, args->index); - if (IS_ERR(cmd)) { - struct nbd_sock *nsock = config->socks[args->index]; + struct nbd_reply reply; - mutex_lock(&nsock->tx_lock); - nbd_mark_nsock_dead(nbd, nsock, 1); - mutex_unlock(&nsock->tx_lock); + if (nbd_read_reply(nbd, args->index, &reply)) + break; + + cmd = nbd_handle_reply(nbd, args->index, &reply); + if (IS_ERR(cmd)) break; - } rq = blk_mq_rq_from_pdu(cmd); if (likely(!blk_should_fake_timeout(rq->q))) blk_mq_complete_request(rq); } + + nsock = config->socks[args->index]; + mutex_lock(&nsock->tx_lock); + nbd_mark_nsock_dead(nbd, nsock, 1); + mutex_unlock(&nsock->tx_lock); + nbd_config_put(nbd); atomic_dec(&config->recv_threads); wake_up(&config->recv_wq);