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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 158C9C433E0 for ; Tue, 23 Feb 2021 13:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CB9B64DBD for ; Tue, 23 Feb 2021 13:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229886AbhBWNyg (ORCPT ); Tue, 23 Feb 2021 08:54:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbhBWNyd (ORCPT ); Tue, 23 Feb 2021 08:54:33 -0500 Received: from mail-wm1-x32f.google.com (mail-wm1-x32f.google.com [IPv6:2a00:1450:4864:20::32f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 194CBC061786; Tue, 23 Feb 2021 05:53:53 -0800 (PST) Received: by mail-wm1-x32f.google.com with SMTP id l13so2509007wmg.5; Tue, 23 Feb 2021 05:53:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=6tw76VnuLjFMgn4T9bkfd6VafA8xKP4Ai1as7ZXDqK8=; b=EWoz4W1c3moghCzHWSkNfyPb2a9fzaRkvlbUo3+PzQgCiRjMJaVYCcfyVEUkKMgKKZ CeLMt2Jubkr5tBxyktTslceNBqg+VrZ3ogB5hGd7hFP8gtNmqeQdh2fTnPvf7mKf7ofs ZV6t6vwMXKNGWW8JhXxz/yAgvDT3FO+VVv0HETZ4WOZveKAXcy9ZzqiEdCAgirsMDDA9 CyeV9a32OTD93vFbPCEvO6nbWTH+Ad0Ip2RkFj81dASHg8A+b/2iihGnoB+6+P4bXPIY cd3dbXxxydPFUxAPosPWM+djIgHd1sSijWqykv3LDUnj1eQhodN3TF46ZOQ7iDbNXLNK FExw== 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:autocrypt:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=6tw76VnuLjFMgn4T9bkfd6VafA8xKP4Ai1as7ZXDqK8=; b=oPO4OKKq9oPIESr2zlEI9kfOSXVZpIbvl36gAFQbK5mWb++UWf8pBkecKzj0WrR4Bp S2w5/ElMshgK65HECC/tdh5HsV8FiALq44xNpXwjQH3EZ7mjCrONhnMegr/6NPbmptzT nrZOsDyDagV54xRHeIxqKbvXuL5hZ+Tt4mEF7mIXqmZE8JiUPg101ns1gvcDGtPO8MCR ouIG6CjgC6Ch2qJclGGqt2Wm+zr6Ktp1OLu+2nBUkkrFHoE5v8ZBnzvOXiDCLzwwgeLo byC+qqYXa4PB9LRoKGEeflKcgRh/l+UTR/KL2wuEjpPd3EpyXaElXar32YpxHtgrcd8h lprQ== X-Gm-Message-State: AOAM532qeEqSW/jWOz4KtNfw9ctlDnKeTDelubqTNkss3p/Miz1Tk2pj yidmcyjMr0NfwsDQgZAsu40= X-Google-Smtp-Source: ABdhPJwSlYkhRpoHY8gfXgCF/0newcJwAPpOWODvyjNoJybBOjC3CtBTLMxhQbuEFWvHw8znwaTX5A== X-Received: by 2002:a1c:41c3:: with SMTP id o186mr25305633wma.7.1614088431816; Tue, 23 Feb 2021 05:53:51 -0800 (PST) Received: from [192.168.8.157] ([148.252.132.56]) by smtp.gmail.com with ESMTPSA id o9sm841748wmc.8.2021.02.23.05.53.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Feb 2021 05:53:51 -0800 (PST) Subject: Re: possible deadlock in io_link_timeout_fn To: syzbot , axboe@kernel.dk, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <00000000000097f98905bc00fd53@google.com> From: Pavel Begunkov Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Message-ID: <5003d05e-4fd9-5d0b-86ed-4e81b48ccf76@gmail.com> Date: Tue, 23 Feb 2021 13:50:00 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: <00000000000097f98905bc00fd53@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 23/02/2021 13:35, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 31caf8b2 Merge branch 'linus' of git://git.kernel.org/pub/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11c64f12d00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5a8f3a57fabb4015 > dashboard link: https://syzkaller.appspot.com/bug?extid=9a512c5bdc15635eab70 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9a512c5bdc15635eab70@syzkaller.appspotmail.com Ok, that IRQ recycling stuff kicks in. I guess we can take work_clean out of spin, I'll try it out this evening. Either, Jen's io-wq patches go 5.12 in the end, and it would probably be solved naturally. > > ===================================================== > WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected > 5.11.0-syzkaller #0 Not tainted > ----------------------------------------------------- > syz-executor.0/12185 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: > ffff888013db4820 (&fs->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] > ffff888013db4820 (&fs->lock){+.+.}-{2:2}, at: io_req_clean_work fs/io_uring.c:1405 [inline] > ffff888013db4820 (&fs->lock){+.+.}-{2:2}, at: io_dismantle_req+0x90f/0xf90 fs/io_uring.c:2051 > > and this task is already holding: > ffff88806bea6718 (&ctx->completion_lock){-...}-{2:2}, at: io_req_complete_post+0x4e/0x920 fs/io_uring.c:1923 > which would create a new lock dependency: > (&ctx->completion_lock){-...}-{2:2} -> (&fs->lock){+.+.}-{2:2} > > but this new dependency connects a HARDIRQ-irq-safe lock: > (&ctx->completion_lock){-...}-{2:2} > > ... which became HARDIRQ-irq-safe at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > io_link_timeout_fn+0xbf/0x720 fs/io_uring.c:6495 > __run_hrtimer kernel/time/hrtimer.c:1519 [inline] > __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583 > hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] > __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 > asm_call_irq_on_stack+0xf/0x20 > __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] > run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] > sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1100 > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635 > __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] > _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199 > spin_unlock_irq include/linux/spinlock.h:404 [inline] > io_queue_linked_timeout+0x194/0x1f0 fs/io_uring.c:6541 > __io_queue_sqe+0x32f/0xdb0 fs/io_uring.c:6607 > __io_req_task_submit+0x18e/0x240 fs/io_uring.c:2344 > __tctx_task_work fs/io_uring.c:2204 [inline] > tctx_task_work+0x12b/0x330 fs/io_uring.c:2230 > task_work_run+0xdd/0x1a0 kernel/task_work.c:140 > tracehook_notify_signal include/linux/tracehook.h:212 [inline] > handle_signal_work kernel/entry/common.c:145 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x221/0x250 kernel/entry/common.c:208 > __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > to a HARDIRQ-irq-unsafe lock: > (&fs->lock){+.+.}-{2:2} > > ... which became HARDIRQ-irq-unsafe at: > ... > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > set_fs_pwd+0x85/0x2a0 fs/fs_struct.c:39 > init_chdir+0x106/0x14e fs/init.c:54 > devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] > devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > other info that might help us debug this: > > Possible interrupt unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&fs->lock); > local_irq_disable(); > lock(&ctx->completion_lock); > lock(&fs->lock); > > lock(&ctx->completion_lock); > > *** DEADLOCK *** > > 1 lock held by syz-executor.0/12185: > #0: ffff88806bea6718 (&ctx->completion_lock){-...}-{2:2}, at: io_req_complete_post+0x4e/0x920 fs/io_uring.c:1923 > > the dependencies between HARDIRQ-irq-safe lock and the holding lock: > -> (&ctx->completion_lock){-...}-{2:2} { > IN-HARDIRQ-W at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > io_link_timeout_fn+0xbf/0x720 fs/io_uring.c:6495 > __run_hrtimer kernel/time/hrtimer.c:1519 [inline] > __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583 > hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] > __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 > asm_call_irq_on_stack+0xf/0x20 > __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] > run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] > sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1100 > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635 > __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] > _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199 > spin_unlock_irq include/linux/spinlock.h:404 [inline] > io_queue_linked_timeout+0x194/0x1f0 fs/io_uring.c:6541 > __io_queue_sqe+0x32f/0xdb0 fs/io_uring.c:6607 > __io_req_task_submit+0x18e/0x240 fs/io_uring.c:2344 > __tctx_task_work fs/io_uring.c:2204 [inline] > tctx_task_work+0x12b/0x330 fs/io_uring.c:2230 > task_work_run+0xdd/0x1a0 kernel/task_work.c:140 > tracehook_notify_signal include/linux/tracehook.h:212 [inline] > handle_signal_work kernel/entry/common.c:145 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x221/0x250 kernel/entry/common.c:208 > __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x44/0xae > INITIAL USE at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > io_req_complete_post+0x4e/0x920 fs/io_uring.c:1923 > __io_req_complete fs/io_uring.c:1963 [inline] > io_req_complete fs/io_uring.c:1968 [inline] > io_queue_sqe+0xa3b/0xfa0 fs/io_uring.c:6620 > io_submit_sqe fs/io_uring.c:6707 [inline] > io_submit_sqes+0x15f5/0x2b60 fs/io_uring.c:6939 > __do_sys_io_uring_enter+0x1154/0x1f50 fs/io_uring.c:9454 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xae > } > ... key at: [] __key.9+0x0/0x40 > ... acquired at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > io_req_clean_work fs/io_uring.c:1405 [inline] > io_dismantle_req+0x90f/0xf90 fs/io_uring.c:2051 > io_req_complete_post+0xf6/0x920 fs/io_uring.c:1933 > __io_req_complete fs/io_uring.c:1963 [inline] > io_req_complete fs/io_uring.c:1968 [inline] > io_cancel_defer_files fs/io_uring.c:8945 [inline] > io_uring_cancel_task_requests+0x67e/0xea0 fs/io_uring.c:9052 > __io_uring_files_cancel+0x110/0x1b0 fs/io_uring.c:9140 > io_uring_files_cancel include/linux/io_uring.h:65 [inline] > do_exit+0x2fe/0x2ae0 kernel/exit.c:780 > do_group_exit+0x125/0x310 kernel/exit.c:922 > get_signal+0x42c/0x2100 kernel/signal.c:2773 > arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 > handle_signal_work kernel/entry/common.c:147 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 > __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > the dependencies between the lock to be acquired > and HARDIRQ-irq-unsafe lock: > -> (&fs->lock){+.+.}-{2:2} { > HARDIRQ-ON-W at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > set_fs_pwd+0x85/0x2a0 fs/fs_struct.c:39 > init_chdir+0x106/0x14e fs/init.c:54 > devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] > devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > SOFTIRQ-ON-W at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > set_fs_pwd+0x85/0x2a0 fs/fs_struct.c:39 > init_chdir+0x106/0x14e fs/init.c:54 > devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] > devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > INITIAL USE at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > set_fs_pwd+0x85/0x2a0 fs/fs_struct.c:39 > init_chdir+0x106/0x14e fs/init.c:54 > devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] > devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > } > ... key at: [] __key.1+0x0/0x40 > ... acquired at: > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > io_req_clean_work fs/io_uring.c:1405 [inline] > io_dismantle_req+0x90f/0xf90 fs/io_uring.c:2051 > io_req_complete_post+0xf6/0x920 fs/io_uring.c:1933 > __io_req_complete fs/io_uring.c:1963 [inline] > io_req_complete fs/io_uring.c:1968 [inline] > io_cancel_defer_files fs/io_uring.c:8945 [inline] > io_uring_cancel_task_requests+0x67e/0xea0 fs/io_uring.c:9052 > __io_uring_files_cancel+0x110/0x1b0 fs/io_uring.c:9140 > io_uring_files_cancel include/linux/io_uring.h:65 [inline] > do_exit+0x2fe/0x2ae0 kernel/exit.c:780 > do_group_exit+0x125/0x310 kernel/exit.c:922 > get_signal+0x42c/0x2100 kernel/signal.c:2773 > arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 > handle_signal_work kernel/entry/common.c:147 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 > __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > stack backtrace: > CPU: 3 PID: 12185 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0xfa/0x151 lib/dump_stack.c:120 > print_bad_irq_dependency kernel/locking/lockdep.c:2460 [inline] > check_irq_usage.cold+0x50d/0x744 kernel/locking/lockdep.c:2689 > check_prev_add kernel/locking/lockdep.c:2940 [inline] > check_prevs_add kernel/locking/lockdep.c:3059 [inline] > validate_chain kernel/locking/lockdep.c:3674 [inline] > __lock_acquire+0x2b2c/0x54c0 kernel/locking/lockdep.c:4900 > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:354 [inline] > io_req_clean_work fs/io_uring.c:1405 [inline] > io_dismantle_req+0x90f/0xf90 fs/io_uring.c:2051 > io_req_complete_post+0xf6/0x920 fs/io_uring.c:1933 > __io_req_complete fs/io_uring.c:1963 [inline] > io_req_complete fs/io_uring.c:1968 [inline] > io_cancel_defer_files fs/io_uring.c:8945 [inline] > io_uring_cancel_task_requests+0x67e/0xea0 fs/io_uring.c:9052 > __io_uring_files_cancel+0x110/0x1b0 fs/io_uring.c:9140 > io_uring_files_cancel include/linux/io_uring.h:65 [inline] > do_exit+0x2fe/0x2ae0 kernel/exit.c:780 > do_group_exit+0x125/0x310 kernel/exit.c:922 > get_signal+0x42c/0x2100 kernel/signal.c:2773 > arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 > handle_signal_work kernel/entry/common.c:147 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 > __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x465ef9 > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffb56aa0218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: 0000000000000000 RBX: 000000000056bf68 RCX: 0000000000465ef9 > RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68 > RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c > R13: 00007fff198147ff R14: 00007ffb56aa0300 R15: 0000000000022000 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > -- Pavel Begunkov