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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 2824AC7618B for ; Tue, 23 Jul 2019 12:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E535C21903 for ; Tue, 23 Jul 2019 12:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389971AbfGWMsc (ORCPT ); Tue, 23 Jul 2019 08:48:32 -0400 Received: from mail-io1-f70.google.com ([209.85.166.70]:48485 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389896AbfGWMsJ (ORCPT ); Tue, 23 Jul 2019 08:48:09 -0400 Received: by mail-io1-f70.google.com with SMTP id z19so47138538ioi.15 for ; Tue, 23 Jul 2019 05:48:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=WX8mXrwL9YnlGxhS0vNPmZsDMJDdSwdsae3+5KoJhw4=; b=A9yEu2shZerJ9vD3F/VZiihSs4vZwCg2bkcIsiSNND1+BvqdJMqdYguY0oQ1vm143O Y0mIzAN07p+KTtOcrX9ru3BofmdT1Uni9+j3btakL36ldpxX3PTKPSYCzj6judXnPMev my23FnsrNQLSJSNTHBAB2LoGmfpqno4VJerQgbGThOpjKGgBfI0KVtZHkMRtyMqVYezQ pL5TiLDrT/AxY3z+7wnRYmPybcu4XDdCUI5XRJVH6QahUjS9W9EHCYP6xwh5Oxc3/0T/ f+SMyv5DsKGxynprrnreYYew68mTQxq/uqi7fA+e39E1sXMqPvGsCIND2ZmTUOcqYXl2 iHwg== X-Gm-Message-State: APjAAAU0uG/whSHuza5HV1ewMxkNEOqSyvDCP0Kr/cjMnEELAev3+9yU 9EMM6QNvP1yOFmbFOLruFUjPF0kT6mxuxAAZzEN9i/u/Gx51 X-Google-Smtp-Source: APXvYqxpmRTm1Q/eLgar1kQxpMbltpDcfrexteHauNl6iqi5+sJBwkZZ7lKROTzwaUT5ASIZSEZsuPjD74hWprlZLSMaB2qyAmVU MIME-Version: 1.0 X-Received: by 2002:a5e:8a46:: with SMTP id o6mr38159236iom.36.1563886088591; Tue, 23 Jul 2019 05:48:08 -0700 (PDT) Date: Tue, 23 Jul 2019 05:48:08 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c7a7e4058e589ad1@google.com> Subject: INFO: task hung in hwrng_unregister From: syzbot To: andreyknvl@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=1266ca64600000 kernel config: https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae dashboard link: https://syzkaller.appspot.com/bug?extid=823cb2bdae0c63b2cb9f compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=143d46f4600000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1789853fa00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+823cb2bdae0c63b2cb9f@syzkaller.appspotmail.com INFO: task kworker/0:0:5 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #15 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:0 D26088 5 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0x96/0x240 /kernel/sched/core.c:3509 schedule_timeout+0x682/0xb20 /kernel/time/timer.c:1783 do_wait_for_common /kernel/sched/completion.c:83 [inline] __wait_for_common /kernel/sched/completion.c:104 [inline] wait_for_common /kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 /kernel/sched/completion.c:136 kthread_stop+0xe6/0x5a0 /kernel/kthread.c:559 hwrng_unregister+0x190/0x210 /drivers/char/hw_random/core.c:535 chaoskey_disconnect+0x1b2/0x200 /drivers/usb/misc/chaoskey.c:231 usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423 __device_release_driver /drivers/base/dd.c:1081 [inline] device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112 bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556 device_del+0x460/0xb80 /drivers/base/core.c:2274 usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199 hub_port_connect /drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline] port_event /drivers/usb/core/hub.c:5359 [inline] hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441 process_one_work+0x905/0x1570 /kernel/workqueue.c:2269 process_scheduled_works /kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 /kernel/workqueue.c:2417 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 INFO: task kworker/1:1:21 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #15 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:1 D25576 21 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0x96/0x240 /kernel/sched/core.c:3509 schedule_timeout+0x682/0xb20 /kernel/time/timer.c:1783 do_wait_for_common /kernel/sched/completion.c:83 [inline] __wait_for_common /kernel/sched/completion.c:104 [inline] wait_for_common /kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 /kernel/sched/completion.c:136 kthread_stop+0xe6/0x5a0 /kernel/kthread.c:559 hwrng_unregister+0x190/0x210 /drivers/char/hw_random/core.c:535 chaoskey_disconnect+0x1b2/0x200 /drivers/usb/misc/chaoskey.c:231 usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423 __device_release_driver /drivers/base/dd.c:1081 [inline] device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112 bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556 device_del+0x460/0xb80 /drivers/base/core.c:2274 usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199 hub_port_connect /drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline] port_event /drivers/usb/core/hub.c:5359 [inline] hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441 process_one_work+0x905/0x1570 /kernel/workqueue.c:2269 process_scheduled_works /kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 /kernel/workqueue.c:2417 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 INFO: task kworker/0:2:107 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #15 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:2 D25688 107 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0x96/0x240 /kernel/sched/core.c:3509 schedule_timeout+0x682/0xb20 /kernel/time/timer.c:1783 do_wait_for_common /kernel/sched/completion.c:83 [inline] __wait_for_common /kernel/sched/completion.c:104 [inline] wait_for_common /kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 /kernel/sched/completion.c:136 kthread_stop+0xe6/0x5a0 /kernel/kthread.c:559 hwrng_unregister+0x190/0x210 /drivers/char/hw_random/core.c:535 chaoskey_disconnect+0x1b2/0x200 /drivers/usb/misc/chaoskey.c:231 usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423 __device_release_driver /drivers/base/dd.c:1081 [inline] device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112 bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556 device_del+0x460/0xb80 /drivers/base/core.c:2274 usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199 hub_port_connect /drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline] port_event /drivers/usb/core/hub.c:5359 [inline] hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441 process_one_work+0x905/0x1570 /kernel/workqueue.c:2269 process_scheduled_works /kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 /kernel/workqueue.c:2417 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 INFO: task kworker/1:2:108 blocked for more than 144 seconds. Not tainted 5.2.0-rc6+ #15 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D26088 108 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0x96/0x240 /kernel/sched/core.c:3509 schedule_timeout+0x682/0xb20 /kernel/time/timer.c:1783 do_wait_for_common /kernel/sched/completion.c:83 [inline] __wait_for_common /kernel/sched/completion.c:104 [inline] wait_for_common /kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 /kernel/sched/completion.c:136 kthread_stop+0xe6/0x5a0 /kernel/kthread.c:559 hwrng_unregister+0x190/0x210 /drivers/char/hw_random/core.c:535 chaoskey_disconnect+0x1b2/0x200 /drivers/usb/misc/chaoskey.c:231 usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423 __device_release_driver /drivers/base/dd.c:1081 [inline] device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112 bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556 device_del+0x460/0xb80 /drivers/base/core.c:2274 usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199 hub_port_connect /drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline] port_event /drivers/usb/core/hub.c:5359 [inline] hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441 process_one_work+0x905/0x1570 /kernel/workqueue.c:2269 process_scheduled_works /kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 /kernel/workqueue.c:2417 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 INFO: task kworker/1:0:1743 blocked for more than 144 seconds. Not tainted 5.2.0-rc6+ #15 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:0 D26088 1743 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0x96/0x240 /kernel/sched/core.c:3509 schedule_timeout+0x682/0xb20 /kernel/time/timer.c:1783 do_wait_for_common /kernel/sched/completion.c:83 [inline] __wait_for_common /kernel/sched/completion.c:104 [inline] wait_for_common /kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 /kernel/sched/completion.c:136 kthread_stop+0xe6/0x5a0 /kernel/kthread.c:559 hwrng_unregister+0x190/0x210 /drivers/char/hw_random/core.c:535 chaoskey_disconnect+0x1b2/0x200 /drivers/usb/misc/chaoskey.c:231 usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423 __device_release_driver /drivers/base/dd.c:1081 [inline] device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112 bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556 device_del+0x460/0xb80 /drivers/base/core.c:2274 usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199 hub_port_connect /drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline] port_event /drivers/usb/core/hub.c:5359 [inline] hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441 process_one_work+0x905/0x1570 /kernel/workqueue.c:2269 process_scheduled_works /kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 /kernel/workqueue.c:2417 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 5 locks held by kworker/0:0/5: #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81a/0x1570 /kernel/workqueue.c:2240 #1: 00000000c0e8b754 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x84e/0x1570 /kernel/workqueue.c:2244 #2: 00000000b363c0f6 (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #2: 00000000b363c0f6 (&dev->mutex){....}, at: hub_event+0x179/0x3550 /drivers/usb/core/hub.c:5387 #3: 0000000085e6ee8d (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #3: 0000000085e6ee8d (&dev->mutex){....}, at: usb_disconnect+0x91/0x830 /drivers/usb/core/hub.c:2190 #4: 00000000f0ac3a42 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x4c0 /drivers/base/dd.c:1109 5 locks held by kworker/1:1/21: #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81a/0x1570 /kernel/workqueue.c:2240 #1: 00000000e4cc4967 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x84e/0x1570 /kernel/workqueue.c:2244 #2: 000000009fad33ce (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #2: 000000009fad33ce (&dev->mutex){....}, at: hub_event+0x179/0x3550 /drivers/usb/core/hub.c:5387 #3: 0000000054332177 (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #3: 0000000054332177 (&dev->mutex){....}, at: usb_disconnect+0x91/0x830 /drivers/usb/core/hub.c:2190 #4: 0000000024af6192 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x4c0 /drivers/base/dd.c:1109 1 lock held by khungtaskd/23: #0: 00000000c34a6907 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 /kernel/locking/lockdep.c:5147 5 locks held by kworker/0:2/107: #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81a/0x1570 /kernel/workqueue.c:2240 #1: 00000000123183b4 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x84e/0x1570 /kernel/workqueue.c:2244 #2: 0000000052b6f3e1 (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #2: 0000000052b6f3e1 (&dev->mutex){....}, at: hub_event+0x179/0x3550 /drivers/usb/core/hub.c:5387 #3: 0000000074cd949e (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #3: 0000000074cd949e (&dev->mutex){....}, at: usb_disconnect+0x91/0x830 /drivers/usb/core/hub.c:2190 #4: 000000004b055abd (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x4c0 /drivers/base/dd.c:1109 5 locks held by kworker/1:2/108: #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81a/0x1570 /kernel/workqueue.c:2240 #1: 00000000e35f89a1 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x84e/0x1570 /kernel/workqueue.c:2244 #2: 00000000b09f111f (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #2: 00000000b09f111f (&dev->mutex){....}, at: hub_event+0x179/0x3550 /drivers/usb/core/hub.c:5387 #3: 000000006b5fbeae (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #3: 000000006b5fbeae (&dev->mutex){....}, at: usb_disconnect+0x91/0x830 /drivers/usb/core/hub.c:2190 #4: 0000000081dcaa24 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x4c0 /drivers/base/dd.c:1109 1 lock held by rsyslogd/1609: #0: 00000000d7f3ff94 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 /fs/file.c:801 2 locks held by getty/1699: #0: 00000000bc736fb1 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 0000000014dfa3bf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1700: #0: 00000000be14d894 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 00000000ff0e9bac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1701: #0: 00000000d0e4fddf (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 000000004b19a9d4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1702: #0: 00000000c1b6c003 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 0000000099fff3a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1703: #0: 000000008cc2d327 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 0000000056f83ac4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1704: #0: 000000000eebfa14 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 00000000a2f569ec (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 2 locks held by getty/1705: #0: 0000000055305a29 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:272 #1: 000000001cc6455d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 /drivers/tty/n_tty.c:2156 5 locks held by kworker/1:0/1743: #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000008d4a8324 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81a/0x1570 /kernel/workqueue.c:2240 #1: 00000000f376c2ba ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x84e/0x1570 /kernel/workqueue.c:2244 #2: 000000007ee3f09e (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #2: 000000007ee3f09e (&dev->mutex){....}, at: hub_event+0x179/0x3550 /drivers/usb/core/hub.c:5387 #3: 00000000250c1adb (&dev->mutex){....}, at: device_lock /./include/linux/device.h:1208 [inline] #3: 00000000250c1adb (&dev->mutex){....}, at: usb_disconnect+0x91/0x830 /drivers/usb/core/hub.c:2190 #4: 00000000538ed281 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x4c0 /drivers/base/dd.c:1109 5 locks held by kworker/0:1/1745: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.2.0-rc6+ #15 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack /lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e /lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x48/0x87 /lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1bd /lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace /./include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks /kernel/hung_task.c:205 [inline] watchdog+0x989/0xe20 /kernel/hung_task.c:289 kthread+0x30b/0x410 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt /./arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt /./arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0x28/0x2b0 /arch/x86/kernel/process.c:580 --- This bug is generated by a bot. 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