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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 E99AFC4320A for ; Wed, 1 Sep 2021 09:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF758600D4 for ; Wed, 1 Sep 2021 09:47:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243802AbhIAJss (ORCPT ); Wed, 1 Sep 2021 05:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232817AbhIAJsq (ORCPT ); Wed, 1 Sep 2021 05:48:46 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06D76C061575; Wed, 1 Sep 2021 02:47:50 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id v20-20020a1cf714000000b002e71f4d2026so3417048wmh.1; Wed, 01 Sep 2021 02:47:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=aMg3NODH8Ey3eCpI+t2A6v0su9qdk4Ke/uuuhl535ws=; b=OrjvQJy00TNBAB3Ai2WQzeBw7QDdfslCsOrFIzWbyyX/zH8LJzYNFTNdDwd56x+hQj AydFWj50UXXPBVEXMdqtrZ+JRDN1lbbd6EC5NeJ1d//auqIvRiPljYD6r7Teg2o1YfwA VidXwRernBLawiBDsAWSxy4w8qroxDmU4i8hZy03Urp0SK3H6eqkBho4/tLoRXomXsAT Uw9Rd5fW2uofWrVmDbRkwgcWoMcFQsvF8473Du1u86GcCLdYfx/9ocnKaitxZMxS+jvx BoVoHUs/8NMT8jtMyK1ngmKXHDyJFHFLHOuzfpXAW23PgCCnW08BVs1jaRDpa11L9rmO oiQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=aMg3NODH8Ey3eCpI+t2A6v0su9qdk4Ke/uuuhl535ws=; b=LSaM5JnnHJ8XH7K+K2l0PAiOFP4oHoGQuoU6xYU/OwISPzqbC3eR9HO2FkZXhHKGjm ejT4LJkZAhHMso5aARpeiSTohI1xSOaJwXLxl6kdaEYj4Zzv182y7wggVVn1LezZY2Fw wryR3bmOVgLqNFrbizSzZ0H5jJPBNWorsxk2I82ovLms6SixBPbA4z++krmYnfgSfd/2 sjpdhuTd9kulHeLUz1RbUjsvR776u77dbOGStLi4qsXjrEhK8QqBsiJtvGnaFF9fqlyb On5NqYtviV5byYLKsjFqNIYSiD8dRGbA4Ey9DWk1CNd+XmtIYE/m6oJyvETFY9Q0gJBN yEZw== X-Gm-Message-State: AOAM531Feq23dKqdaYjGHMQXGFLdeRHONOZSwKLx57p6/mhvVVjqUp0G xCcX+tDjOBg5s3G/VWMfChHi7HLvgvA= X-Google-Smtp-Source: ABdhPJycsBV7lugiVztxDKyEIVMLSWx1ESn1pMe8wIzVuPyGIArAIZkJW0HZ9AJNMpyx4QfgMubvUA== X-Received: by 2002:a05:600c:1457:: with SMTP id h23mr8701530wmi.143.1630489668414; Wed, 01 Sep 2021 02:47:48 -0700 (PDT) Received: from [192.168.8.197] ([85.255.233.192]) by smtp.gmail.com with ESMTPSA id x21sm4883743wmi.15.2021.09.01.02.47.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 01 Sep 2021 02:47:48 -0700 (PDT) Subject: Re: [RFC PATCH] io_uring: stop issue failed request to fix panic To: =?UTF-8?B?546L6LSH?= , Jens Axboe , "open list:IO_URING" , open list References: From: Pavel Begunkov Message-ID: Date: Wed, 1 Sep 2021 10:47:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/1/21 10:39 AM, 王贇 wrote: > We observed panic: > BUG: kernel NULL pointer dereference, address:0000000000000028 > [skip] > Oops: 0000 [#1] SMP PTI > CPU: 1 PID: 737 Comm: a.out Not tainted 5.14.0+ #58 > Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 > RIP: 0010:vfs_fadvise+0x1e/0x80 > [skip] > Call Trace: > ? tctx_task_work+0x111/0x2a0 > io_issue_sqe+0x524/0x1b90 Most likely it was fixed yesterday. Can you try? https://git.kernel.dk/cgit/linux-block/log/?h=for-5.15/io_uring Or these two patches in particular https://git.kernel.dk/cgit/linux-block/commit/?h=for-5.15/io_uring&id=c6d3d9cbd659de8f2176b4e4721149c88ac096d4 https://git.kernel.dk/cgit/linux-block/commit/?h=for-5.15/io_uring&id=b8ce1b9d25ccf81e1bbabd45b963ed98b2222df8 > This is caused by io_wq_submit_work() calling io_issue_sqe() > on a failed fadvise request, and the io_init_req() return error > before initialize the file for it, lead into the panic when > vfs_fadvise() try to access 'req->file'. > > This patch add the missing check & handle for failed request > before calling io_issue_sqe(). > > Signed-off-by: Michael Wang > --- > fs/io_uring.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 6f35b12..bfec7bf 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -2214,7 +2214,8 @@ static void io_req_task_submit(struct io_kiocb *req, bool *locked) > > io_tw_lock(ctx, locked); > /* req->task == current here, checking PF_EXITING is safe */ > - if (likely(!(req->task->flags & PF_EXITING))) > + if (likely(!(req->task->flags & PF_EXITING) && > + !(req->flags & REQ_F_FAIL))) > __io_queue_sqe(req); > else > io_req_complete_failed(req, -EFAULT); > @@ -6704,7 +6705,10 @@ static void io_wq_submit_work(struct io_wq_work *work) > > if (!ret) { > do { > - ret = io_issue_sqe(req, 0); > + if (likely(!(req->flags & REQ_F_FAIL))) > + ret = io_issue_sqe(req, 0); > + else > + io_req_complete_failed(req, -EFAULT); > /* > * We can get EAGAIN for polled IO even though we're > * forcing a sync submission from here, since we can't > -- Pavel Begunkov