INFO: task kworker/0:2:95 blocked for more than 143 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:2 D26128 95 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x682/0xb20 kernel/time/timer.c:1871 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+0x17a/0x780 kernel/kthread.c:559 hwrng_unregister+0x24f/0x330 drivers/char/hw_random/core.c:556 chaoskey_disconnect+0x216/0x290 drivers/usb/misc/chaoskey.c:232 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1168 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2677 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264 worker_thread+0x96/0xe20 kernel/workqueue.c:2410 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 3 locks held by kworker/0:1/12: #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881da227dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 #2: ffff8881d494b200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d494b200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5509 1 lock held by khungtaskd/23: #0: ffffffff87109060 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5331 5 locks held by kworker/1:2/83: 5 locks held by kworker/0:2/95: #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8ec6d28 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881d58ffdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 #2: ffff8881d4924200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d4924200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5509 #3: ffff8881d42f6200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8881d42f6200 (&dev->mutex){....}, at: usb_disconnect+0x91/0x900 drivers/usb/core/hub.c:2202 #4: ffff8881d886c190 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x500 drivers/base/dd.c:1165 1 lock held by rsyslogd/1678: #0: ffff8881d017b4e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/1769: #0: ffff8881ce8d7090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000083b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1770: #0: ffff8881ce5e0090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000082f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1771: #0: ffff8881ce7cd090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1772: #0: ffff8881ce77a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008572e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1773: #0: ffff8881ce779090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1774: #0: ffff8881ce7ce090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008472e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1775: #0: ffff8881cea0a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000081f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.4/6753: #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1649 [inline] #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: mnt_want_write_file+0x63/0x110 fs/namespace.c:412 #1: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #1: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_ioctl+0xa53/0x4510 fs/ext4/ioctl.c:858 3 locks held by syz-executor.4/6754: #0: ffff8881c65cc860 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline] #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: vfs_write+0x474/0x5c0 fs/read_write.c:557 #2: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_buffered_write_iter+0xb3/0x4a0 fs/ext4/file.c:264 3 locks held by syz-executor.4/6756: #0: ffff8881d92d3260 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline] #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: vfs_write+0x474/0x5c0 fs/read_write.c:557 #2: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff8881ab0d3468 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_buffered_write_iter+0xb3/0x4a0 fs/ext4/file.c:264 2 locks held by syz-executor.5/6760: #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1649 [inline] #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: mnt_want_write_file+0x63/0x110 fs/namespace.c:412 #1: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #1: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_ioctl+0xa53/0x4510 fs/ext4/ioctl.c:858 3 locks held by syz-executor.5/6761: #0: ffff8881d996a860 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline] #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: vfs_write+0x474/0x5c0 fs/read_write.c:557 #2: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_buffered_write_iter+0xb3/0x4a0 fs/ext4/file.c:264 3 locks held by syz-executor.5/6762: #0: ffff8881d996ad60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline] #1: ffff8881d436e410 (sb_writers#3){.+.+}, at: vfs_write+0x474/0x5c0 fs/read_write.c:557 #2: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff8881ab0d44c8 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_buffered_write_iter+0xb3/0x4a0 fs/ext4/file.c:264 2 locks held by syz-executor.3/6766: #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1649 [inline] #0: ffff8881d436e410 (sb_writers#3){.+.+}, at: mnt_want_write_file+0x63/0x110 fs/namespace.c:412 #1: ffff8881d2490b78 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:791 [inline] #1: ffff8881d2490b78 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_ioctl+0xa53/0x4510 fs/ext4/ioctl.c:858 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.6.0-rc5-syzkaller #0 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+0xef/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1db/0x207 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+0xa99/0xfd0 kernel/hung_task.c:289 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1823 Comm: syz-executor.3 Not tainted 5.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:284 Code: 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 cc fe ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 ae fe ff ff 0f 1f 40 00 RSP: 0018:ffff8881b0aefd88 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 000000000000c350 RCX: ffffffff8130b9b6 RDX: 0000000000000000 RSI: 0000000000000078 RDI: 0000000000000000 RBP: 1ffff1103615dfb3 R08: ffff8881cd6b6200 R09: ffffed103615dfc6 R10: ffffed103615dfc5 R11: ffff8881b0aefe2f R12: 00000000000f4240 R13: 0000000000000001 R14: 0000000000000078 R15: 0000000000000001 FS: 0000000001498940(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f89ffe4bdb8 CR3: 00000001b0ad4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dl_prio include/linux/sched/deadline.h:13 [inline] dl_task include/linux/sched/deadline.h:20 [inline] hrtimer_nanosleep+0xee/0x3a0 kernel/time/hrtimer.c:1922 __do_sys_nanosleep kernel/time/hrtimer.c:1961 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1948 [inline] __x64_sys_nanosleep+0x1dc/0x260 kernel/time/hrtimer.c:1948 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45acf0 Code: c0 5b 5d c3 66 0f 1f 44 00 00 8b 04 24 48 83 c4 18 5b 5d c3 66 0f 1f 44 00 00 83 3d 61 dc 82 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 d4 d1 fb ff c3 48 83 ec 08 e8 ea 46 00 00 RSP: 002b:00007ffe49c0c668 EFLAGS: 00000246 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 000000000002da8c RCX: 000000000045acf0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffe49c0c670 RBP: 00000000000000e6 R08: 0000000000000001 R09: 0000000001498940 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00007ffe49c0c6c0 R14: 000000000002da75 R15: 00007ffe49c0c6d0