From mboxrd@z Thu Jan 1 00:00:00 1970 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 74289C2BB3F for ; Wed, 15 Nov 2023 19:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234760AbjKOTjj (ORCPT ); Wed, 15 Nov 2023 14:39:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234770AbjKOTji (ORCPT ); Wed, 15 Nov 2023 14:39:38 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 742CDA4 for ; Wed, 15 Nov 2023 11:39:35 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1470C433C9; Wed, 15 Nov 2023 19:39:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700077175; bh=qBCPzqFJLgtJxCt/CoZd0Zk9nCyuNkmG3aEjo5OEmzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ra3HEkcvMDTgA5OkClQzUbNoQTOY/m1JptcWUMhJ2qnPSPeryDozCV4aioTLgOCrO bRuRpNX0xKluoOmfcjmLCbcwIun6ZfbChTqO9hL0Ahha+s+ZE24BEG/OUw+5LkBqbh SuqsrBn5FaAr6xsufeWo9vcivMZcEhgcb+UtAGhw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe Subject: [PATCH 6.5 545/550] io_uring/net: ensure socket is marked connected on connect retry Date: Wed, 15 Nov 2023 14:18:49 -0500 Message-ID: <20231115191638.696418658@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191600.708733204@linuxfoundation.org> References: <20231115191600.708733204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jens Axboe commit f8f9ab2d98116e79d220f1d089df7464ad4e026d upstream. io_uring does non-blocking connection attempts, which can yield some unexpected results if a connect request is re-attempted by an an application. This is equivalent to the following sync syscall sequence: sock = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP); connect(sock, &addr, sizeof(addr); ret == -1 and errno == EINPROGRESS expected here. Now poll for POLLOUT on sock, and when that returns, we expect the socket to be connected. But if we follow that procedure with: connect(sock, &addr, sizeof(addr)); you'd expect ret == -1 and errno == EISCONN here, but you actually get ret == 0. If we attempt the connection one more time, then we get EISCON as expected. io_uring used to do this, but turns out that bluetooth fails with EBADFD if you attempt to re-connect. Also looks like EISCONN _could_ occur with this sequence. Retain the ->in_progress logic, but work-around a potential EISCONN or EBADFD error and only in those cases look at the sock_error(). This should work in general and avoid the odd sequence of a repeated connect request returning success when the socket is already connected. This is all a side effect of the socket state being in a CONNECTING state when we get EINPROGRESS, and only a re-connect or other related operation will turn that into CONNECTED. Cc: stable@vger.kernel.org Fixes: 3fb1bd688172 ("io_uring/net: handle -EINPROGRESS correct for IORING_OP_CONNECT") Link: https://github.com/axboe/liburing/issues/980 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/net.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) --- a/io_uring/net.c +++ b/io_uring/net.c @@ -1461,16 +1461,6 @@ int io_connect(struct io_kiocb *req, uns int ret; bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; - if (connect->in_progress) { - struct socket *socket; - - ret = -ENOTSOCK; - socket = sock_from_file(req->file); - if (socket) - ret = sock_error(socket->sk); - goto out; - } - if (req_has_async_data(req)) { io = req->async_data; } else { @@ -1490,9 +1480,7 @@ int io_connect(struct io_kiocb *req, uns && force_nonblock) { if (ret == -EINPROGRESS) { connect->in_progress = true; - return -EAGAIN; - } - if (ret == -ECONNABORTED) { + } else if (ret == -ECONNABORTED) { if (connect->seen_econnaborted) goto out; connect->seen_econnaborted = true; @@ -1506,6 +1494,16 @@ int io_connect(struct io_kiocb *req, uns memcpy(req->async_data, &__io, sizeof(__io)); return -EAGAIN; } + if (connect->in_progress) { + /* + * At least bluetooth will return -EBADFD on a re-connect + * attempt, and it's (supposedly) also valid to get -EISCONN + * which means the previous result is good. For both of these, + * grab the sock_error() and use that for the completion. + */ + if (ret == -EBADFD || ret == -EISCONN) + ret = sock_error(sock_from_file(req->file)->sk); + } if (ret == -ERESTARTSYS) ret = -EINTR; out: