INFO: task khugepaged:37 blocked for more than 145 seconds. Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khugepaged state:D stack:24600 pid:37 tgid:37 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_work+0xa37/0xc50 kernel/workqueue.c:4217 __lru_add_drain_all+0x4f6/0x560 mm/swap.c:888 khugepaged_do_scan mm/khugepaged.c:2502 [inline] khugepaged+0x1bf/0x1dc0 mm/khugepaged.c:2571 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 2 locks held by kworker/0:0/8: 1 lock held by khungtaskd/30: #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 1 lock held by khugepaged/37: #0: ffffffff8e9f92c8 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x66/0x560 mm/swap.c:843 3 locks held by kworker/u8:8/3519: 2 locks held by getty/5598: #0: ffff88814ce450a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by kworker/0:3/5844: 2 locks held by kworker/0:4/5855: 2 locks held by kworker/0:1/14169: 4 locks held by kworker/u8:0/23053: #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900034afd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900034afd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc66d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffff88805d471428 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x110/0x2e0 drivers/net/wireguard/device.c:249 1 lock held by syz.5.5491/23888: 1 lock held by syz-executor/23955: #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:__lock_acquire+0xd1d/0x2050 kernel/locking/lockdep.c:5185 Code: 0f 85 8b 0e 00 00 83 3d 20 ce cc 18 00 41 bc 01 00 00 00 75 0a 49 83 fe ff 0f 85 fe 08 00 00 48 89 e8 48 c1 e8 03 80 3c 38 00 <74> 12 48 89 ef e8 e9 3d 8e 00 48 bf 00 00 00 00 00 fc ff df 4c 89 RSP: 0018:ffffc900000074d0 EFLAGS: 00000046 RAX: 1ffff11003958cab RBX: ffff88801cac64d0 RCX: ffffffff81706aab RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff88801cac6558 R08: ffffffff942cc807 R09: 1ffffffff2859900 R10: dffffc0000000000 R11: fffffbfff2859901 R12: 0000000000000000 R13: ffff88801cac64d8 R14: e2c77c5ed61ac569 R15: ffff88801cac6578 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa8caadad58 CR3: 0000000046c76000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:978 [inline] debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1019 slab_free_hook mm/slub.c:2273 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x11f/0x440 mm/slub.c:4727 dummy_timer+0x7f4/0x4620 drivers/usb/gadget/udc/dummy_hcd.c:1987 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x59d/0xd50 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1772 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__schedule+0x5/0x4bd0 kernel/sched/core.c:6546 Code: c7 60 31 04 90 e8 0b ce 2f f6 e9 41 7a 21 00 cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 01 00 RSP: 0018:ffffc900000d78d0 EFLAGS: 00000282 RAX: 83fafbb954078e00 RBX: 1ffff9200001af24 RCX: ffffffff8170cfda RDX: dffffc0000000000 RSI: ffffffff8c0acb40 RDI: 0000000000000001 RBP: ffffc900000d79a0 R08: ffffffff942cc897 R09: 1ffffffff2859912 R10: dffffc0000000000 R11: fffffbfff2859913 R12: 1ffff9200001af1c R13: 1ffff9200001af20 R14: ffffc900000d7900 R15: dffffc0000000000 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7012 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:389 Code: 8c e8 84 87 6f 0a 65 66 8b 05 e4 48 ac 7e 66 85 c0 75 5d bf 01 00 00 00 e8 9d b0 0b 00 e8 38 22 45 00 fb 65 8b 05 a8 48 ac 7e <85> c0 75 05 e8 67 27 a9 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c RSP: 0018:ffffc900000d7a60 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 1ffff9200001af50 RCX: ffffffff8170cfda RDX: dffffc0000000000 RSI: ffffffff8c0acb40 RDI: ffffffff8c610360 RBP: ffffc900000d7b20 R08: ffffffff942cc897 R09: 1ffffffff2859912 R10: dffffc0000000000 R11: fffffbfff2859913 R12: dffffc0000000000 R13: 1ffff9200001af54 R14: ffffc900000d7aa0 R15: 0000000000000201 neigh_periodic_work+0xb35/0xd50 net/core/neighbour.c:1019 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244