INFO: task kworker/u4:3:98 blocked for more than 143 seconds. Not tainted 5.11.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:25752 pid: 98 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x999/0xe70 kernel/sched/core.c:5078 schedule+0x14b/0x200 kernel/sched/core.c:5157 schedule_timeout+0x43/0x250 kernel/time/timer.c:1854 do_wait_for_common+0x266/0x3a0 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 kthread_park+0x10d/0x1c0 kernel/kthread.c:582 io_put_sq_data fs/io_uring.c:7403 [inline] io_sq_thread_stop fs/io_uring.c:7501 [inline] io_finish_async+0x351/0x460 fs/io_uring.c:7508 io_ring_ctx_free fs/io_uring.c:8673 [inline] io_ring_exit_work+0x55/0x4c0 fs/io_uring.c:8766 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 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/u4:3/98: #0: ffff888011069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248 #1: ffffc9000111fd78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250 1 lock held by khungtaskd/1647: #0: ffffffff8c711680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151 2 locks held by kworker/1:2/4587: #0: ffff88801107c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248 #1: ffffc90008b0fd78 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250 1 lock held by in:imklog/8155: #0: ffff88802236a370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:947 1 lock held by syz-executor.0/8475: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 2 locks held by syz-executor.1/8477: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 #1: ffffffff8c715a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c715a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x1e8/0x600 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.2/8479: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.3/8481: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.4/8483: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.5/8485: #0: ffff888147148d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1647 Comm: khungtaskd Not tainted 5.11.0-rc7-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+0x137/0x1be lib/dump_stack.c:120 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xce9/0xd30 kernel/hung_task.c:294 kthread+0x39a/0x3c0 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: 5 Comm: kworker/0:0 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:preempt_count_sub+0x5a/0x160 kernel/sched/core.c:4772 Code: 8b 05 96 ef af 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 1c 81 fb fe 00 00 00 77 07 0f b6 c0 85 c0 74 4f f7 db 65 01 1d 72 ef af 7e <5b> 41 5e c3 e8 ad b7 f6 07 85 c0 74 f3 48 c7 c0 48 ca b3 8d 48 c1 RSP: 0018:ffffc90000ca7708 EFLAGS: 00000293 RAX: 0000000000000002 RBX: 00000000ffffffff RCX: 0000000000000002 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc90000ca8000 R08: dffffc0000000000 R09: ffffc90000ca7838 R10: fffff52000194f09 R11: 0000000000000000 R12: 1ffffffff1c86556 R13: ffffc90000ca77e8 R14: dffffc0000000000 R15: 1ffff92000194efd FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f795fc0c000 CR3: 00000000246cd000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x1634/0x1e20 arch/x86/kernel/unwind_orc.c:608 arch_stack_walk+0xb2/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xad/0x150 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:356 ____kasan_slab_free+0xe2/0x110 mm/kasan/common.c:362 kasan_slab_free include/linux/kasan.h:192 [inline] slab_free_hook mm/slub.c:1547 [inline] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1580 slab_free mm/slub.c:3143 [inline] kmem_cache_free+0x85/0x160 mm/slub.c:3159 nsim_dev_trap_report drivers/net/netdevsim/dev.c:586 [inline] nsim_dev_trap_report_work+0x7d5/0xb20 drivers/net/netdevsim/dev.c:611 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296