INFO: task syz-executor.1:674 blocked for more than 140 seconds. Not tainted 4.19.80 #0 kobject: 'loop1' (000000009560278e): kobject_uevent_env kobject: 'loop1' (000000009560278e): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: '9p-56' (0000000082611b27): kobject_uevent_env "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28216 674 875 0x80000002 kobject: '9p-56' (0000000082611b27): fill_kobj_path: path = '/devices/virtual/bdi/9p-56' kobject: 'loop5' (0000000085147e48): kobject_uevent_env Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 net_ratelimit: 14 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop5' (0000000085147e48): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (000000009560278e): kobject_uevent_env kobject: 'loop1' (000000009560278e): fill_kobj_path: path = '/devices/virtual/block/loop1' schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop3' (0000000032108166): kobject_uevent_env kobject: 'loop3' (0000000032108166): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop0' (00000000d5193de4): kobject_uevent_env kobject: 'loop0' (00000000d5193de4): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (000000009560278e): kobject_uevent_env kobject: 'loop1' (000000009560278e): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (0000000085147e48): kobject_uevent_env kobject: 'loop5' (0000000085147e48): fill_kobj_path: path = '/devices/virtual/block/loop5' 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+0x29c/0x440 kernel/sched/completion.c:136 kobject: 'loop3' (0000000032108166): kobject_uevent_env kobject: 'loop3' (0000000032108166): fill_kobj_path: path = '/devices/virtual/block/loop3' kthread_stop+0x116/0x6c0 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x1e0/0x6e2 drivers/media/platform/vivid/vivid-kthread-cap.c:922 vid_cap_stop_streaming+0x8a/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:256 kobject: 'loop4' (000000002a053dea): kobject_uevent_env kobject: 'loop4' (000000002a053dea): fill_kobj_path: path = '/devices/virtual/block/loop4' __vb2_queue_cancel+0xb1/0x790 drivers/media/common/videobuf2/videobuf2-core.c:1682 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop3' (0000000032108166): kobject_uevent_env kobject: 'kvm' (00000000d0692ffc): kobject_uevent_env kobject: 'loop3' (0000000032108166): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'kvm' (00000000d0692ffc): fill_kobj_path: path = '/devices/virtual/misc/kvm' vb2_core_streamoff+0x60/0x150 drivers/media/common/videobuf2/videobuf2-core.c:1816 __vb2_cleanup_fileio+0x78/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2343 kobject: 'loop1' (000000009560278e): kobject_uevent_env kobject: 'loop1' (000000009560278e): fill_kobj_path: path = '/devices/virtual/block/loop1' IPVS: ftp: loaded support on port[0] = 21 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2070 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:671 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:842 vb2_fop_release+0x75/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:856 kobject: 'lo' (00000000a5d26cd7): kobject_add_internal: parent: 'net', set: 'devices' vivid_fop_release+0x18e/0x430 drivers/media/platform/vivid/vivid-core.c:474 kobject: 'loop5' (0000000085147e48): kobject_uevent_env protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 v4l2_release+0xf9/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x994/0x2fa0 kernel/exit.c:876 kobject: 'lo' (00000000a5d26cd7): kobject_uevent_env do_group_exit+0x135/0x370 kernel/exit.c:979 __do_sys_exit_group kernel/exit.c:990 [inline] __se_sys_exit_group kernel/exit.c:988 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:988 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459cd9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 kobject: 'lo' (00000000a5d26cd7): fill_kobj_path: path = '/devices/virtual/net/lo' RSP: 002b:00007fff472ed7e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 kobject: 'loop5' (0000000085147e48): fill_kobj_path: path = '/devices/virtual/block/loop5' RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000459cd9 kobject: 'queues' (00000000e81c1ef3): kobject_add_internal: parent: 'lo', set: '' kobject: 'loop0' (00000000d5193de4): kobject_uevent_env RDX: 0000000000413901 RSI: 0000000000a76c70 RDI: 0000000000000000 kobject: 'queues' (00000000e81c1ef3): kobject_uevent_env kobject: 'queues' (00000000e81c1ef3): kobject_uevent_env: filter function caused the event to drop! kobject: 'loop0' (00000000d5193de4): fill_kobj_path: path = '/devices/virtual/block/loop0' RBP: 00000000004bf410 R08: 000000000000000c R09: 00007fff472ed8f0 kobject: 'rx-0' (000000001a33e8f2): kobject_add_internal: parent: 'queues', set: 'queues' R10: 0000000001395940 R11: 0000000000000246 R12: 000000000075bfc8 kobject: 'rx-0' (000000001a33e8f2): kobject_uevent_env kobject: 'rx-0' (000000001a33e8f2): fill_kobj_path: path = '/devices/virtual/net/lo/queues/rx-0' kobject: 'loop5' (0000000085147e48): kobject_uevent_env kobject: 'tx-0' (000000008ef42b93): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'tx-0' (000000008ef42b93): kobject_uevent_env kobject: 'tx-0' (000000008ef42b93): fill_kobj_path: path = '/devices/virtual/net/lo/queues/tx-0' kobject: 'loop5' (0000000085147e48): fill_kobj_path: path = '/devices/virtual/block/loop5' R13: 0000000000000003 R14: 0000000000000001 R15: 000000000075bfd4 Showing all locks held in the system: kobject: 'tunl0' (00000000bf1b2e8e): kobject_add_internal: parent: 'net', set: 'devices' 3 locks held by kworker/u4:2/46: 1 lock held by khungtaskd/1038: #0: 0000000057a12c16 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 kobject: 'tunl0' (00000000bf1b2e8e): kobject_uevent_env kobject: 'loop3' (0000000032108166): kobject_uevent_env kobject: 'loop3' (0000000032108166): fill_kobj_path: path = '/devices/virtual/block/loop3' 3 locks held by udevd/3587: kobject: 'tunl0' (00000000bf1b2e8e): fill_kobj_path: path = '/devices/virtual/net/tunl0' IPVS: ftp: loaded support on port[0] = 21 kobject: 'loop4' (000000002a053dea): kobject_uevent_env 1 lock held by rsyslogd/7546: #0: 00000000f83153f3 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 kobject: 'queues' (000000001f2c999c): kobject_add_internal: parent: 'tunl0', set: '' kobject: 'loop4' (000000002a053dea): fill_kobj_path: path = '/devices/virtual/block/loop4' 2 locks held by getty/7668: kobject: 'queues' (000000001f2c999c): kobject_uevent_env kobject: 'loop0' (00000000d5193de4): kobject_uevent_env #0: kobject: 'loop0' (00000000d5193de4): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'queues' (000000001f2c999c): kobject_uevent_env: filter function caused the event to drop! 000000009762dd6c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 kobject: 'loop3' (0000000032108166): kobject_uevent_env #1: 0000000017f77f96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 kobject: 'rx-0' (0000000071adb09b): kobject_add_internal: parent: 'queues', set: 'queues' 2 locks held by getty/7669: kobject: 'loop3' (0000000032108166): fill_kobj_path: path = '/devices/virtual/block/loop3' #0: 00000000cb883776 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000080a98427 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 kobject: 'rx-0' (0000000071adb09b): kobject_uevent_env kobject: 'rx-0' (0000000071adb09b): fill_kobj_path: path = '/devices/virtual/net/tunl0/queues/rx-0' 2 locks held by getty/7670: kobject: 'tx-0' (00000000ba67145b): kobject_add_internal: parent: 'queues', set: 'queues' #0: kobject: 'tx-0' (00000000ba67145b): kobject_uevent_env 00000000dcdf06d4 kobject: 'tx-0' (00000000ba67145b): fill_kobj_path: path = '/devices/virtual/net/tunl0/queues/tx-0' (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000f4ce1c7e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7671: #0: 000000009489cff0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000fa050068 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7672: #0: 000000009e25d917 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b15f7d66 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7673: #0: 00000000cc8138c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000026da0f9d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7674: #0: 00000000460d0c82 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000003d32917e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by kworker/u4:8/18571: #0: 00000000fc6f3432 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9656 [inline] #0: 00000000fc6f3432 (&rq->lock){-.-.}, at: pick_next_task_fair+0xfae/0x1580 kernel/sched/fair.c:6837 #1: 0000000057a12c16 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6054 2 locks held by syz-executor.1/15150: #0: 00000000f2e0c811 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x337 net/core/net_namespace.c:434 #1: 0000000056609109 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 3 locks held by syz-executor.1/15271: #0: 00000000f2e0c811 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x337 net/core/net_namespace.c:434 #1: 0000000056609109 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #2: 00000000d9d47277 (&caifn->caifdevs.lock){+.+.}, at: caif_exit_net+0x2f0/0x7d0 net/caif/caif_dev.c:518 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1038 Comm: khungtaskd Not tainted 4.19.80 #0 kobject: '9p-56' (0000000082611b27): kobject_uevent_env 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 kobject: '9p-56' (0000000082611b27): fill_kobj_path: path = '/devices/virtual/bdi/9p-56' ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: kobject: '9p-56' (0000000082611b27): kobject_cleanup, parent (null) NMI backtrace for cpu 0 CPU: 0 PID: 822 Comm: syz-executor.2 Not tainted 4.19.80 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mark_irqflags kernel/locking/lockdep.c:2990 [inline] RIP: 0010:__lock_acquire+0x538/0x49c0 kernel/locking/lockdep.c:3368 Code: 00 8b 45 28 45 85 c0 41 89 42 24 0f 84 b0 01 00 00 49 8d 7a 21 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 <48> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 11 0b 00 00 4d 8d 62 22 RSP: 0018:ffff8880ae807b70 EFLAGS: 00000802 RAX: 0000000000000000 RBX: 0000000000040000 RCX: 0000000000002000 RDX: 1ffff11013ce51f4 RSI: ffff88809e728f80 RDI: ffff88809e728fa1 RBP: ffff8880ae807d40 R08: 0000000000000001 R09: 0000000000000000 R10: ffff88809e728f80 R11: 0000000000000050 R12: 0000000000000000 R13: 00000000000c2050 R14: ffff88809e728700 R15: 0000000000000000 FS: 0000000001863940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000cb05c8 CR3: 0000000095f6c000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 expire_timers kernel/time/timer.c:1360 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0x451/0x16a0 kernel/time/timer.c:1697 __do_softirq+0x25c/0x921 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1689 [inline] RIP: 0010:vprintk_emit+0x5b8/0x690 kernel/printk/printk.c:1926 Code: 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 0f 85 a2 00 00 00 48 83 3d cc 2a 1d 07 00 74 29 e8 bd ab 15 00 48 89 df 57 9d <0f> 1f 44 00 00 e9 79 fe ff ff e8 a9 ab 15 00 0f 0b e8 a2 ab 15 00 RSP: 0018:ffff88808762fa20 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff88809e728700 RBX: 0000000000000293 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81551b83 RDI: 0000000000000293 RBP: ffff88808762fa68 R08: ffff88809e728700 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000004d R13: 1ffffffff10e48c9 R14: 0000000000000200 R15: ffff8880a8220600 vprintk_default+0x28/0x30 kernel/printk/printk.c:1968 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2001 kobject_cleanup lib/kobject.c:638 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put.cold+0x88/0x2e6 lib/kobject.c:708 put_device drivers/base/core.c:2081 [inline] device_unregister+0x28/0x30 drivers/base/core.c:2193 bdi_unregister+0x46e/0x650 mm/backing-dev.c:949 release_bdi mm/backing-dev.c:965 [inline] kref_put include/linux/kref.h:70 [inline] bdi_put+0x151/0x180 mm/backing-dev.c:974 generic_shutdown_super+0x2b0/0x370 fs/super.c:470 kill_anon_super+0x3e/0x60 fs/super.c:1032 v9fs_kill_super+0x3e/0xa0 fs/9p/vfs_super.c:230 deactivate_locked_super+0x95/0x100 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x1bd/0x1e0 fs/super.c:356 cleanup_mnt+0xbf/0x150 fs/namespace.c:1098 __cleanup_mnt+0x16/0x20 fs/namespace.c:1105 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c707 Code: 64 89 04 25 d0 02 00 00 58 5f ff d0 48 89 c7 e8 2f be ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 9d 8d fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff0231b468 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 000000000014d9e7 RCX: 000000000045c707 RDX: 00000000004039a0 RSI: 0000000000000002 RDI: 00007fff0231b510 RBP: 0000000000001f61 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000005 R11: 0000000000000202 R12: 00007fff0231c5a0 R13: 0000000001864940 R14: 0000000000000000 R15: 00007fff0231c5a0