INFO: task kworker/u4:2:25 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:24088 pid: 25 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:7242 [inline] io_sq_thread_stop+0x452/0x570 fs/io_uring.c:7339 io_finish_async fs/io_uring.c:7346 [inline] io_ring_ctx_free fs/io_uring.c:8501 [inline] io_ring_exit_work+0x102/0x7a0 fs/io_uring.c:8595 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/u4:5:21898 blocked for more than 144 seconds. Not tainted 5.10.0-rc4-next-20201119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:24856 pid:21898 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:7242 [inline] io_sq_thread_stop+0x452/0x570 fs/io_uring.c:7339 io_finish_async fs/io_uring.c:7346 [inline] io_ring_ctx_free fs/io_uring.c:8501 [inline] io_ring_exit_work+0x102/0x7a0 fs/io_uring.c:8595 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/u4:2/25: #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: ffffc90000e0fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 2 locks held by kworker/u4:3/110: #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: ffffc9000123fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 1 lock held by khungtaskd/1652: #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/4899: 1 lock held by in:imklog/8195: #0: ffff888025b385f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 3 locks held by syz-executor.0/8524: #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x217/0x2030 kernel/sched/core.c:4936 #1: ffff8880b9f20088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x305/0x440 kernel/sched/psi.c:833 #2: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: compound_head include/linux/page-flags.h:184 [inline] #2: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: lock_page_memcg+0x33/0x4f0 mm/memcontrol.c:2135 3 locks held by kworker/u4:6/29457: 2 locks held by kworker/u4:5/21898: #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: ffffc9001806fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 2 locks held by syz-executor.0/17265: 2 locks held by syz-executor.4/17269: 2 locks held by syz-executor.1/17270: 3 locks held by syz-executor.3/17272: #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x217/0x2030 kernel/sched/core.c:4936 #1: ffff8880b9f20088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x305/0x440 kernel/sched/psi.c:833 #2: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #2: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: ttwu_queue kernel/sched/core.c:3142 [inline] #2: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: try_to_wake_up+0x533/0x12f0 kernel/sched/core.c:3422 1 lock held by syz-executor.0/17281: 1 lock held by syz-executor.5/17287: #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9f34f98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x217/0x2030 kernel/sched/core.c:4936 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1652 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201119-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: 17296 Comm: syz-executor.4 Not tainted 5.10.0-rc4-next-20201119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:select_task_rq_fair+0x17/0x3450 kernel/sched/fair.c:6718 Code: e9 53 ff ff ff e8 a9 53 64 00 eb 93 0f 1f 80 00 00 00 00 41 57 89 d0 41 56 41 55 41 54 55 53 48 83 ec 70 83 e0 10 48 89 3c 24 <89> 74 24 10 89 54 24 30 89 44 24 48 74 4a 65 4c 8b 24 25 00 f0 01 RSP: 0018:ffffc9000a0bf9b8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff92001417f51 RCX: 1ffffffff15c880a RDX: 0000000000000008 RSI: 0000000000000000 RDI: ffff8880205f0000 RBP: ffff8880205f0000 R08: ffff8880205f0010 R09: ffffffff8ced3ecf R10: fffffbfff19da7d9 R11: 0000000000000000 R12: 0000000000000287 R13: ffff8880205f0848 R14: ffff8880205f0040 R15: ffff8880205f0368 FS: 00007f3c27125700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc31346108 CR3: 000000002ce32000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: select_task_rq kernel/sched/core.c:2777 [inline] try_to_wake_up+0x361/0x12f0 kernel/sched/core.c:3412 wake_up_process kernel/sched/core.c:3492 [inline] wake_up_q+0x96/0x100 kernel/sched/core.c:597 futex_wake+0x3e9/0x490 kernel/futex.c:1625 do_futex+0x322/0x1a60 kernel/futex.c:3770 __do_sys_futex+0x2a2/0x470 kernel/futex.c:3828 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3c27124cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000118bf28 RCX: 000000000045deb9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000118bf2c RBP: 000000000118bf20 R08: 0000000000000016 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffec9f6923f R14: 00007f3c271259c0 R15: 000000000118bf2c