From patchwork Mon Dec 28 12:48:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 354784 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=unavailable 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 D2C63C43217 for ; Mon, 28 Dec 2020 14:47:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC7B4229C5 for ; Mon, 28 Dec 2020 14:47:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502992AbgL1OYG (ORCPT ); Mon, 28 Dec 2020 09:24:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:60182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502984AbgL1OYF (ORCPT ); Mon, 28 Dec 2020 09:24:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 744282245C; Mon, 28 Dec 2020 14:23:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609165404; bh=F0FnHfMERRw5xu6UhLVLDLTxoiecxzuy0pehTAoY8tI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YIdvop3oy8YITbyZGjlKjS7paaDHHJg7S+83nJjLDI1K7tGcLuJS/uOQpkNVaHKfs ZAlW76QzIVun19UOYsTANgxM7XtexL/IFnxKvYGq3sBpz13mZrDk+ToMyDl6VfAjzv ZSbg1sCQHAJusZO8T/uKWev+D5jSvQ/M0lIUwz4k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c9937dfb2303a5f18640@syzkaller.appspotmail.com, Pavel Begunkov , Jens Axboe Subject: [PATCH 5.10 520/717] io_uring: fix double io_uring free Date: Mon, 28 Dec 2020 13:48:38 +0100 Message-Id: <20201228125045.874173758@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228125020.963311703@linuxfoundation.org> References: <20201228125020.963311703@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pavel Begunkov commit 9faadcc8abe4b83d0263216dc3a6321d5bbd616b upstream. Once we created a file for current context during setup, we should not call io_ring_ctx_wait_and_kill() directly as it'll be done by fput(file) Cc: stable@vger.kernel.org # 5.10 Reported-by: syzbot+c9937dfb2303a5f18640@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov [axboe: fix unused 'ret' for !CONFIG_UNIX] Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 71 +++++++++++++++++++++++++++++++--------------------------- 1 file changed, 39 insertions(+), 32 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -9195,55 +9195,52 @@ static int io_allocate_scq_urings(struct return 0; } +static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file) +{ + int ret, fd; + + fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC); + if (fd < 0) + return fd; + + ret = io_uring_add_task_file(ctx, file); + if (ret) { + put_unused_fd(fd); + return ret; + } + fd_install(fd, file); + return fd; +} + /* * Allocate an anonymous fd, this is what constitutes the application * visible backing of an io_uring instance. The application mmaps this * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, * we have to tie this fd to a socket for file garbage collection purposes. */ -static int io_uring_get_fd(struct io_ring_ctx *ctx) +static struct file *io_uring_get_file(struct io_ring_ctx *ctx) { struct file *file; +#if defined(CONFIG_UNIX) int ret; - int fd; -#if defined(CONFIG_UNIX) ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, &ctx->ring_sock); if (ret) - return ret; + return ERR_PTR(ret); #endif - ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC); - if (ret < 0) - goto err; - fd = ret; - file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, O_RDWR | O_CLOEXEC); - if (IS_ERR(file)) { - put_unused_fd(fd); - ret = PTR_ERR(file); - goto err; - } - #if defined(CONFIG_UNIX) - ctx->ring_sock->file = file; -#endif - ret = io_uring_add_task_file(ctx, file); - if (ret) { - fput(file); - put_unused_fd(fd); - goto err; + if (IS_ERR(file)) { + sock_release(ctx->ring_sock); + ctx->ring_sock = NULL; + } else { + ctx->ring_sock->file = file; } - fd_install(fd, file); - return fd; -err: -#if defined(CONFIG_UNIX) - sock_release(ctx->ring_sock); - ctx->ring_sock = NULL; #endif - return ret; + return file; } static int io_uring_create(unsigned entries, struct io_uring_params *p, @@ -9251,6 +9248,7 @@ static int io_uring_create(unsigned entr { struct user_struct *user = NULL; struct io_ring_ctx *ctx; + struct file *file; bool limit_mem; int ret; @@ -9397,13 +9395,22 @@ static int io_uring_create(unsigned entr goto err; } + file = io_uring_get_file(ctx); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err; + } + /* * Install ring fd as the very last thing, so we don't risk someone * having closed it before we finish setup */ - ret = io_uring_get_fd(ctx); - if (ret < 0) - goto err; + ret = io_uring_install_fd(ctx, file); + if (ret < 0) { + /* fput will clean it up */ + fput(file); + return ret; + } trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); return ret;