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=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 1783CC43461 for ; Wed, 9 Sep 2020 16:39:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D530720C09 for ; Wed, 9 Sep 2020 16:39:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="y8KsdU2x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730567AbgIIQjK (ORCPT ); Wed, 9 Sep 2020 12:39:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731114AbgIIQhQ (ORCPT ); Wed, 9 Sep 2020 12:37:16 -0400 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D1E1C06135D for ; Wed, 9 Sep 2020 07:03:36 -0700 (PDT) Received: by mail-il1-x143.google.com with SMTP id a8so2452259ilk.1 for ; Wed, 09 Sep 2020 07:03:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=kCsxeCMw67opcoElUs8hZzWLlvUYaz8JdahayB2RUI4=; b=y8KsdU2xS4h9wwHh/xYDwErwKAwdbag1RHnw+sM66m/fustnVCcke5hzrzLLhpqjyI gAKCWN9X6Ps6x4mAijLqE21trmg9mvsJQ6ZXE0ar9XW5AIXWCAZTNu+/gqEJ6wq0O0gL AzlVewdt+lb/VWNKuLkTogy0q7/FP96IucjOTs0oY3gRRxpBURUZKYXuGXdIarA/8MZG bVbuGmOJ4V48/zvhddDGTpiR5+vFcOkBtV4tQZyGNtf7K6xTmUEgpvSiEmEAXSDc32oN uTt5aC7e2b47Bf/C77XLGczztZb6xRGZ3YIqp8kpjfAi8rNQJ7u+jP0IMx/wbKphG5W1 NfiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=kCsxeCMw67opcoElUs8hZzWLlvUYaz8JdahayB2RUI4=; b=MEXzm35I+YZsN76FOUlzFDNS6UG2BelBOeKPjtbuShdqpoRPdMe8miGGvUUFrs9lcN haHUApQgiSlucPyyFXoox3dTg1Onk56rNqv8GyPeqrDKag2uB6DLvzknFrHEYnCVqEV3 ++iXeaD6YO1BysjLeuiiMHZ2axooNRP4KpaqTzEP6gCWC9NLcmlwcJ3yjybzwymP2Hon +p5xMpGBInPOmeqOuM01bKHX/4x0gW6Q1i4hKdJaHb4iFJPPmfQD8kaCUdrbwIEIkgYh kpI7NsD5hXOwtsVnXnq6UO/V8kARtFSvogt7sQMkigvU6pp9Ff2bSTfQHzLLCVxu0xCl m13w== X-Gm-Message-State: AOAM531bzg8YJT1Uve6030GaE9VcbB2xgxYk6m//5xSu4fSxDg1POTw0 jUAfprOfa+Ey/W23QL2/QsDyOu9FwhiniAkV X-Google-Smtp-Source: ABdhPJywiqVd3crHHoKQ2WPdED4AxcZSebQ/f1P0yVO+Jydm2uWgdHboDeu9R4fZh5S89cAdslOriA== X-Received: by 2002:a92:985a:: with SMTP id l87mr3668939ili.2.1599660214146; Wed, 09 Sep 2020 07:03:34 -0700 (PDT) Received: from [192.168.1.10] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id c2sm1464286ilo.7.2020.09.09.07.03.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Sep 2020 07:03:33 -0700 (PDT) Subject: Re: INFO: task hung in io_sq_thread_stop To: Stefano Garzarella , syzbot Cc: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk References: <00000000000030a45905aedd879d@google.com> <20200909100355.ibz4jc5ctnwbmy5v@steredhat> From: Jens Axboe Message-ID: Date: Wed, 9 Sep 2020 08:03:32 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200909100355.ibz4jc5ctnwbmy5v@steredhat> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/9/20 4:03 AM, Stefano Garzarella wrote: > On Wed, Sep 09, 2020 at 01:49:22AM -0700, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: dff9f829 Add linux-next specific files for 20200908 >> git tree: linux-next >> console output: https://syzkaller.appspot.com/x/log.txt?x=112f880d900000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=37b3426c77bda44c >> dashboard link: https://syzkaller.appspot.com/bug?extid=3c23789ea938faaef049 >> compiler: gcc (GCC) 10.1.0-syz 20200507 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17c082a5900000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1474f5f9900000 >> >> Bisection is inconclusive: the first bad commit could be any of: >> >> d730b1a2 io_uring: add IOURING_REGISTER_RESTRICTIONS opcode >> 7ec3d1dd io_uring: allow disabling rings during the creation > > I'm not sure it is related, but while rebasing I forgot to update the > right label in the error path. > > Since the check of ring state is after the increase of ctx refcount, we > need to decrease it jumping to 'out' label instead of 'out_fput': > diff --git a/fs/io_uring.c b/fs/io_uring.c > index d00eb6bf6ce9..f35da516095a 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -8649,7 +8649,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, > goto out_fput; > > if (ctx->flags & IORING_SETUP_R_DISABLED) > - goto out_fput; > + goto out; > > /* > * For SQ polling, the thread will do all submissions and completions. > > I'll send a patch ASAP and check if it solves this issue. I think that's a separate bug, it's definitely a bug. So please do send the fix, thanks. -- Jens Axboe