rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=d12/1/0x4000000000000000 softirq=70112/70112 fqs=40 (detected by 1, t=10502 jiffies, g=135413, q=415) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30530 Comm: syz-executor.0 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:28 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:check_memory_region+0x44/0x180 mm/kasan/generic.c:192 Code: 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 c7 0f 86 05 01 00 00 49 83 e9 01 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 ca <48> c1 ed 03 49 c1 ea 03 48 01 c5 49 01 c2 48 89 e8 49 8d 5a 01 48 RSP: 0018:ffffc90000007b00 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8159a47f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8c59ab60 RBP: ffffffff8c59ab60 R08: 0000000000000000 R09: ffffffff8c59ab67 R10: ffffffff8c59ab67 R11: 0000000000000001 R12: ffff888052f48500 R13: 0000000000000002 R14: ffff88808b30fb00 R15: 0000000000000a3c FS: 00000000014a5940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004ec210 CR3: 0000000090823000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:56 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] check_wait_context kernel/locking/lockdep.c:4055 [inline] __lock_acquire+0x49f/0x56e0 kernel/locking/lockdep.c:4330 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:4959 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] advance_sched+0x4f/0x990 net/sched/sch_taprio.c:699 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xe0/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:585 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_release+0x481/0x8d0 kernel/locking/lockdep.c:4980 Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 7f 03 00 00 48 83 3d 03 d8 5a 08 00 0f 84 a9 01 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c5 48 c7 45 00 RSP: 0018:ffffc900021b78c8 EFLAGS: 00000282 RAX: 1ffffffff1369c11 RBX: ffff888052f48500 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff89a68318 RDI: 0000000000000282 RBP: 1ffff92000436f1b R08: 0000000000000001 R09: ffff888052f48dc8 R10: fffffbfff155da49 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff86709868 R14: 0000000000000002 R15: ffff888052f48500 __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x12/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2237 [inline] nf_ct_iterate_cleanup+0x88/0x330 net/netfilter/nf_conntrack_core.c:2261 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2346 [inline] nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2331 masq_device_event+0xae/0xe0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2027 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] dev_close_many+0x30b/0x650 net/core/dev.c:1628 rollback_registered_many+0x3af/0xf60 net/core/dev.c:8945 rollback_registered net/core/dev.c:9013 [inline] unregister_netdevice_queue+0x2dd/0x570 net/core/dev.c:10094 unregister_netdevice include/linux/netdevice.h:2754 [inline] __tun_detach+0xff6/0x1310 drivers/net/tun.c:691 tun_detach drivers/net/tun.c:708 [inline] tun_chr_close+0xd9/0x180 drivers/net/tun.c:3423 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:239 [inline] __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:269 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x415ee1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc639b3c20 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000415ee1 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000081796b9d R09: 0000000000000000 R10: 00007ffc639b3d10 R11: 0000000000000293 R12: 000000000078c900 R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac rcu: rcu_preempt kthread starved for 10422 jiffies! g135413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29112 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3458 [inline] __schedule+0x8ea/0x2210 kernel/sched/core.c:4219 schedule+0xd0/0x2a0 kernel/sched/core.c:4294 schedule_timeout+0x148/0x250 kernel/time/timer.c:1908 rcu_gp_fqs_loop kernel/rcu/tree.c:1874 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2044 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293