INFO: task kworker/u4:0:8 blocked for more than 143 seconds. Not tainted 5.11.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:23768 pid: 8 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 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:7276 [inline] io_sq_thread_stop+0x42a/0x570 fs/io_uring.c:7374 io_finish_async fs/io_uring.c:7381 [inline] io_ring_ctx_free fs/io_uring.c:8554 [inline] io_ring_exit_work+0xac/0x730 fs/io_uring.c:8646 process_one_work+0x98d/0x15f0 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/u4:0/8: #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000cefda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 2 locks held by kworker/1:0/17: #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000d8fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 1 lock held by khungtaskd/1646: #0: ffffffff8b363860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 3 locks held by kworker/u4:5/3146: 1 lock held by systemd-udevd/4887: 1 lock held by in:imklog/8165: #0: ffff888018f9a130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949 2 locks held by syz-executor.0/8503: #0: ffff888023140d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 #1: ffffffff8b36bf68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8b36bf68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f2/0x610 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.2/8507: #0: ffff888023140d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.3/8509: #0: ffff888023140d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.4/8511: #0: ffff888023140d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.5/8662: #0: ffff888023140d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 4 locks held by systemd-udevd/21713: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1646 Comm: khungtaskd Not tainted 5.11.0-rc1-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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 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: 4882 Comm: systemd-journal Not tainted 5.11.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:stack_trace_consume_entry+0xb/0x160 kernel/stacktrace.c:82 Code: 1b 4d 11 00 48 c7 c1 c0 6c 4d 89 31 d2 be 80 01 00 00 48 c7 c7 c0 6a 4d 89 e9 31 a2 86 00 cc 48 b8 00 00 00 00 00 fc ff df 55 <53> 48 89 fb 48 83 c7 10 48 89 fa 48 83 ec 08 48 c1 ea 03 0f b6 04 RSP: 0018:ffffc900017b7830 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: ffffffff816129f0 RCX: ffffc900017b78d0 RDX: 1ffff920002f6f11 RSI: ffffffff81612bdc RDI: ffffc900017b78f8 RBP: ffffc900017b78c8 R08: ffffffff8d64f99e R09: 0000000000000001 R10: 0000000000082083 R11: 0000000000000001 R12: ffffc900017b78f8 R13: 0000000000000000 R14: ffff888014e541c0 R15: ffffc900017b7c58 FS: 00007f924a3078c0(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000016b9e60 CR3: 00000000141b1000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x6d/0xe0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:356 ____kasan_slab_free+0xb0/0xe0 mm/kasan/common.c:362 kasan_slab_free include/linux/kasan.h:188 [inline] __cache_free mm/slab.c:3424 [inline] kmem_cache_free+0x58/0x1c0 mm/slab.c:3697 putname+0xe1/0x120 fs/namei.c:259 filename_parentat+0x4b1/0x560 fs/namei.c:2420 filename_create+0x9e/0x490 fs/namei.c:3452 user_path_create fs/namei.c:3527 [inline] do_mkdirat+0xa0/0x2d0 fs/namei.c:3667 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f92495c3687 Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc253f1838 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffc253f48a0 RCX: 00007f92495c3687 RDX: 0000000000000000 RSI: 00000000000001ed RDI: 0000561ca4e3b8c0 RBP: 00007ffc253f1870 R08: 0000561ca31f43e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 0000561ca4e3b8c0 R15: 00007ffc253f1eb0