From patchwork Mon Jun 12 19:56:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13277263 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68113C7EE2F for ; Mon, 12 Jun 2023 19:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbjFLT4e (ORCPT ); Mon, 12 Jun 2023 15:56:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229836AbjFLT4b (ORCPT ); Mon, 12 Jun 2023 15:56:31 -0400 Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E0D9102 for ; Mon, 12 Jun 2023 12:56:30 -0700 (PDT) Received: by mail-io1-xd29.google.com with SMTP id ca18e2360f4ac-7747cc8bea0so39432839f.1 for ; Mon, 12 Jun 2023 12:56:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1686599789; x=1689191789; h=content-transfer-encoding:subject:from:to:content-language :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=r9ofeHvqvAt6ShY55oFXmS+4m8FlIbTOy+uS+/xJl7E=; b=XgCoNy0eO2koQDx8zhHoFRk3HC9C8URPs39CipKnvYYSoySg8gvZ97I3+qizzJFdIs fQLz0c+KDG74QMw176Pj4ef9awpMdFnZSyNJ68A1Kmx0epmtGCpkw5H1sV5LZTm3J443 U9KQc7bZgRaDfuazLrp4qGFMJ9cKRJ5PJphSF1bd2qAY/vxChxMFzeFchis55vmKmTDM loGodc2ZJ23hzWS+oGgd2i7xolFZLph4sraTym8Pj4x71aw9JVbvCiIL4EMp+P+q6PMS 8o7GjtJUafFra8PBxd35+U0aMImWPjCMJXlN4O/XrQKuINgnr1RDaKUCm2kUfBgshYe/ 54ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686599789; x=1689191789; h=content-transfer-encoding:subject:from:to:content-language :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=r9ofeHvqvAt6ShY55oFXmS+4m8FlIbTOy+uS+/xJl7E=; b=O7WTwYmek8N8QsjHPc1HxKUXAEtPy27AeO7TmlZ8ODTdCDN7O6DC2+XUPXKj0Y6U0Q am4m4z0f8qoMD3P3DL2v3RWY/8j49wQ8CkNLF+IQxEt2084RpqXBTxu7C8+dySgFSs7u sDOF2tlt5cu8bIxoQNlHfuh5ZyDVftRcHxLGF0xywrKcuzcRDeHEIVrZuWq9HkIlyG21 Pq5cAVhMMcCdQzhdUVG8Ot2x5fGbQv+Vq33i6ZJE8ebtj3jIxsM/CRliXxQWv/jBQUgp eyl/p/bqYJab/1xnhWUBAVdBHMw3C5efoKKden2fONOKtuEKjNALXIbliS43w/3KqI1m S0PQ== X-Gm-Message-State: AC+VfDzuCbBv0dXy4E2W6dfAjoGYrXHEfA7d+QR+ZQYTVWGX1kwcyRhV BYWPzSnKKc3OD9CrEuT4Boe+wv11JdbSw0HQrYY= X-Google-Smtp-Source: ACHHUZ4hZENqvHX6Y3KFejDSwHfY8TjG7pWH5/cE1QElektrLU5D0gxBRWbFZM3+allGWyAyCZCDcQ== X-Received: by 2002:a6b:690a:0:b0:77a:ee79:652 with SMTP id e10-20020a6b690a000000b0077aee790652mr5019559ioc.1.1686599789344; Mon, 12 Jun 2023 12:56:29 -0700 (PDT) Received: from [192.168.1.94] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id o14-20020a02cc2e000000b0041f6957b290sm2941505jap.93.2023.06.12.12.56.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Jun 2023 12:56:28 -0700 (PDT) Message-ID: <0b0d4411-c8fd-4272-770b-e030af6919a0@kernel.dk> Date: Mon, 12 Jun 2023 13:56:27 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Content-Language: en-US To: io-uring From: Jens Axboe Subject: [PATCH] io_uring/net: save msghdr->msg_control for retries Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org If the application sets ->msg_control and we have to later retry this command, or if it got queued with IOSQE_ASYNC to begin with, then we need to retain the original msg_control value. This is due to the net stack overwriting this field with an in-kernel pointer, to copy it in. Hitting that path for the second time will now fail the copy from user, as it's attempting to copy from a non-user address. Link: https://github.com/axboe/liburing/issues/880 Signed-off-by: Jens Axboe diff --git a/io_uring/net.c b/io_uring/net.c index 89e839013837..51b0f7fbb4f5 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -65,6 +65,7 @@ struct io_sr_msg { u16 addr_len; u16 buf_group; void __user *addr; + void __user *msg_control; /* used only for send zerocopy */ struct io_kiocb *notif; }; @@ -195,11 +196,15 @@ static int io_sendmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + int ret; iomsg->msg.msg_name = &iomsg->addr; iomsg->free_iov = iomsg->fast_iov; - return sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags, + ret = sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags, &iomsg->free_iov); + /* save msg_control as sys_sendmsg() overwrites it */ + sr->msg_control = iomsg->msg.msg_control; + return ret; } int io_send_prep_async(struct io_kiocb *req) @@ -297,6 +302,7 @@ int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) if (req_has_async_data(req)) { kmsg = req->async_data; + kmsg->msg.msg_control = sr->msg_control; } else { ret = io_sendmsg_copy_hdr(req, &iomsg); if (ret)