INFO: task kworker/u4:2:53 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201218-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:24848 pid: 53 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 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_put_sq_data fs/io_uring.c:7269 [inline] io_sq_thread_stop+0x42a/0x570 fs/io_uring.c:7367 io_finish_async fs/io_uring.c:7374 [inline] io_ring_ctx_free fs/io_uring.c:8547 [inline] io_ring_exit_work+0xac/0x730 fs/io_uring.c:8639 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: 2 locks held by kworker/1:1/32: #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2246 #1: ffffc90000e3fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2250 2 locks held by kworker/u4:2/53: #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: ffffc90000f2fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2250 1 lock held by khungtaskd/1666: #0: ffffffff8b793ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254 1 lock held by systemd-udevd/4909: 1 lock held by in:imklog/8200: 2 locks held by syz-executor.0/8510: #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 #1: ffffffff8b79dfe8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8b79dfe8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4ff/0x620 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.1/8512: #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.2/8514: #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.3/8516: #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.5/8623: #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_target net/netfilter/x_tables.c:234 [inline] #0: ffff888021810d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_target+0xa3/0x280 net/netfilter/x_tables.c:226 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1666 Comm: khungtaskd Not tainted 5.10.0-next-20201218-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13057 Comm: kworker/u4:8 Not tainted 5.10.0-next-20201218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: phy13 ieee80211_iface_work RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3502 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3521 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3576 [inline] RIP: 0010:__lock_acquire+0x1749/0x54b0 kernel/locking/lockdep.c:4832 Code: 08 74 59 49 bd 00 00 00 00 00 fc ff df 48 8b 54 24 08 eb 06 48 83 eb 08 74 42 48 8d 7b 18 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <0f> 85 7c 27 00 00 48 8b 43 18 48 39 c2 0f 84 62 f5 ff ff 48 8d 7b RSP: 0018:ffffc9001627fa18 EFLAGS: 00000046 RAX: 1ffffffff1def1cb RBX: ffffffff8ef78e40 RCX: ffffffff81589f72 RDX: 33813ee98d28c7bb RSI: 0000000000000008 RDI: ffffffff8ef78e58 RBP: ffff888028043600 R08: 0000000000000000 R09: ffffffff8f51f7b7 R10: fffffbfff1ea3ef6 R11: 0000000000000000 R12: ffff888028043fb8 R13: dffffc0000000000 R14: 00000000000041aa R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a12649000 CR3: 0000000012129000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x750 kernel/locking/lockdep.c:5402 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 try_to_wake_up+0x98/0x13f0 kernel/sched/core.c:3335 wake_up_worker kernel/workqueue.c:837 [inline] process_one_work+0x7aa/0x1630 kernel/workqueue.c:2238 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