From patchwork Wed May 18 08:40:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12853353 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 E5A0EC433FE for ; Wed, 18 May 2022 08:40:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233433AbiERIkb (ORCPT ); Wed, 18 May 2022 04:40:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233426AbiERIk3 (ORCPT ); Wed, 18 May 2022 04:40:29 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD7921078A7 for ; Wed, 18 May 2022 01:40:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=aYeW7fe3tqt7eOZhO6qodf1YLqFtMMH8JlWFnC3q7gs=; b=PAExOTorQo2Vt9Fy4qzCi5Rt/G pDM4nFbNXFUxNksoitZzN17X39tSGIV1fn2vc/DuSU7TboOsc5iA9axdDDloUAZPDu9kmBqZoqC6s iFb9bcn9PLcQ3o06p615GkCMVP6dZK3hB7TbfrVmaLweINxXBWWCMXTsBehznjpFKUG87ZSgrTvKL dpROGVngMlhdHtVg4gxZmEkFKQH1vdMJm/YNg7/ZUrEQIPCsH63x/6HVEp0YeNJM1NqOjjQUsSLz7 dInCAf8fcn0LYUZF3IaLgF9oy8UtymN2tKHn8ERQyFfkaxZ5IsfWabPOrILHp7GMsTe3JOkfdfBm6 5KEdQS7g==; Received: from [2001:4bb8:19a:7bdf:8143:492c:c3b:39b6] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrFEJ-000dWE-AB; Wed, 18 May 2022 08:40:27 +0000 From: Christoph Hellwig To: axboe@kernel.dk Cc: asml.silence@gmail.com, io-uring@vger.kernel.org Subject: [PATCH 6/6] io_uring: use rcu_dereference in io_close Date: Wed, 18 May 2022 10:40:05 +0200 Message-Id: <20220518084005.3255380-7-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220518084005.3255380-1-hch@lst.de> References: <20220518084005.3255380-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Accessing the file table needs a rcu_dereference_protected(). Signed-off-by: Christoph Hellwig --- fs/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index c9596d551bd67..2b848a8dfc46c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5984,7 +5984,8 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags) spin_unlock(&files->file_lock); goto err; } - file = fdt->fd[close->fd]; + file = rcu_dereference_protected(fdt->fd[close->fd], + lockdep_is_held(&files->file_lock)); if (!file || file->f_op == &io_uring_fops) { spin_unlock(&files->file_lock); file = NULL;