INFO: task kworker/u4:0:8 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201117-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:24032 pid: 8 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1847 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:596 io_put_sq_data fs/io_uring.c:7235 [inline] io_sq_thread_stop+0x452/0x570 fs/io_uring.c:7332 io_finish_async fs/io_uring.c:7339 [inline] io_ring_ctx_free fs/io_uring.c:8494 [inline] io_ring_exit_work+0x102/0x7a0 fs/io_uring.c:8588 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 INFO: task kworker/u4:5:236 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201117-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:24088 pid: 236 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1847 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:596 io_put_sq_data fs/io_uring.c:7235 [inline] io_sq_thread_stop+0x452/0x570 fs/io_uring.c:7332 io_finish_async fs/io_uring.c:7339 [inline] io_ring_ctx_free fs/io_uring.c:8494 [inline] io_ring_exit_work+0x102/0x7a0 fs/io_uring.c:8588 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 2 locks held by kworker/u4:0/8: #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2243 #1: ffffc90000cd7da8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 2 locks held by kworker/u4:5/236: #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2243 #1: ffffc90001a1fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 1 lock held by khungtaskd/1635: #0: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 1 lock held by systemd-udevd/4898: 1 lock held by in:imklog/8187: #0: ffff888012736ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 4 locks held by kworker/0:4/9804: #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888014dd2d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2243 #1: ffffc90016097da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 #2: ffff88801c250218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:731 [inline] #2: ffff88801c250218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x42d0 drivers/usb/core/hub.c:5537 #3: ffff888017e14218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:731 [inline] #3: ffff888017e14218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:887 1 lock held by systemd-udevd/4586: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1635 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4601 Comm: syz-executor.2 Not tainted 5.10.0-rc4-next-20201117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:92 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:109 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:184 [inline] RIP: 0010:check_memory_region+0xde/0x180 mm/kasan/generic.c:193 Code: 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 <74> f2 eb d4 41 bc 08 00 00 00 48 89 ea 45 29 dc 4d 8d 1c 2c eb 0c RSP: 0018:ffffc90017c87478 EFLAGS: 00000046 RAX: fffffbfff1d780ec RBX: fffffbfff1d780ed RCX: ffffffff81562fed RDX: fffffbfff1d780ed RSI: 0000000000000008 RDI: ffffffff8ebc0760 RBP: fffffbfff1d780ec R08: 0000000000000000 R09: ffffffff8ebc0767 R10: fffffbfff1d780ec R11: 0000000000000000 R12: ffff8880119858d0 R13: 000000000000002c R14: 0000000000000002 R15: 0000000000020000 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f28a7e91020 CR3: 0000000020e7d000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:196 [inline] check_wait_context kernel/locking/lockdep.c:4505 [inline] __lock_acquire+0x47d/0x5c00 kernel/locking/lockdep.c:4780 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 rcu_lock_acquire include/linux/rcupdate.h:255 [inline] rcu_read_lock include/linux/rcupdate.h:644 [inline] lock_page_memcg+0x69/0x4f0 mm/memcontrol.c:2150 page_remove_rmap+0x25/0x1360 mm/rmap.c:1334 zap_pte_range mm/memory.c:1264 [inline] zap_pmd_range mm/memory.c:1368 [inline] zap_pud_range mm/memory.c:1397 [inline] zap_p4d_range mm/memory.c:1418 [inline] unmap_page_range+0xe8e/0x26d0 mm/memory.c:1439 unmap_single_vma+0x198/0x300 mm/memory.c:1484 unmap_vmas+0x168/0x2e0 mm/memory.c:1516 exit_mmap+0x2b1/0x530 mm/mmap.c:3236 __mmput+0x122/0x470 kernel/fork.c:1081 mmput+0x53/0x60 kernel/fork.c:1102 exit_mm kernel/exit.c:500 [inline] do_exit+0xaa9/0x29f0 kernel/exit.c:810 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ea/0x1f70 kernel/signal.c:2750 arch_do_signal_or_restart+0x2a6/0x1ea0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007fcf0f26bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: fffffffffffffdfe RBX: 0000000000025fc0 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000040 RBP: 000000000118bf78 R08: 0000000000000000 R09: 0000000020000140 R10: 0000000020000080 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffd9922c2af R14: 00007fcf0f26c9c0 R15: 000000000118bf2c