INFO: task kworker/u4:7:18329 blocked for more than 143 seconds. Not tainted 5.10.0-rc7-next-20201210-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:7 state:D stack:24488 pid:18329 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4325 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5076 schedule+0xcf/0x270 kernel/sched/core.c:5155 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 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_park+0x122/0x1b0 kernel/kthread.c:557 io_sq_thread_park fs/io_uring.c:7348 [inline] io_sq_thread_park fs/io_uring.c:7342 [inline] io_sq_thread_stop+0xfe/0x570 fs/io_uring.c:7366 io_finish_async fs/io_uring.c:7384 [inline] io_ring_ctx_free fs/io_uring.c:8551 [inline] io_ring_exit_work+0xac/0x730 fs/io_uring.c:8643 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 3 locks held by kworker/u4:3/144: 1 lock held by khungtaskd/1664: #0: ffffffff8b78f120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8198: #0: ffff888025bd4ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:923 2 locks held by rs:main Q:Reg/8199: 3 locks held by kworker/u4:7/18329: #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2246 #1: ffffc900029afda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2250 #2: ffff88801ac57070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7347 [inline] #2: ffff88801ac57070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7342 [inline] #2: ffff88801ac57070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_stop+0xd6/0x570 fs/io_uring.c:7366 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1664 Comm: khungtaskd Not tainted 5.10.0-rc7-next-20201210-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+0x3c/0xef 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+0xe75/0x1020 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 144 Comm: kworker/u4:3 Not tainted 5.10.0-rc7-next-20201210-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:319 [inline] RIP: 0010:rcu_is_watching+0x18/0xc0 kernel/rcu/tree.c:1113 Code: 64 57 00 48 8b 34 24 eb bb 66 0f 1f 84 00 00 00 00 00 55 53 65 ff 05 b7 5b a3 7e e8 c2 d2 b7 07 48 c7 c3 40 5e 03 00 83 f8 07 <89> c5 0f 87 81 00 00 00 48 8d 3c ed c0 06 0e 8b 48 b8 00 00 00 00 RSP: 0018:ffffc9000147fb78 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000035e40 RCX: ffffffff81581b78 RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8d7d324f R10: fffffbfff1afa649 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff8b78f120 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffa8d974000 CR3: 0000000012439000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:106 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:121 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x5d3/0x750 kernel/locking/lockdep.c:5408 rcu_lock_acquire include/linux/rcupdate.h:255 [inline] rcu_read_lock include/linux/rcupdate.h:644 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline] batadv_nc_worker+0x12d/0xe80 net/batman-adv/network-coding.c:715 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296