rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=a7d/1/0x4000000000000000 softirq=79056/79058 fqs=3 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16364/1:b..l (detected by 1, t=10502 jiffies, g=111633, q=165) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16177 Comm: syz-executor.3 Not tainted 5.16.0-rc5-next-20211216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0x77/0xc0 kernel/locking/lockdep.c:5117 Code: 53 20 81 e2 ff 1f 00 00 48 39 d0 0f 94 c0 48 83 c4 08 0f b6 c0 5b c3 31 f6 e8 c5 fe ff ff 48 85 c0 75 b2 31 c0 48 83 c4 08 5b 48 83 c4 08 b8 01 00 00 00 5b c3 e8 c8 8e 90 fa 85 c0 74 e4 8b RSP: 0018:ffffc90000007de8 EFLAGS: 00000092 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bb82340 RDI: ffff88803165c4e8 RBP: ffffffff8bb82340 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81676538 R11: 0000000000000000 R12: ffff88803165ba80 R13: ffff88803165c4e8 R14: 00000000ffffffff R15: ffff88803165c4e8 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff3bf9e028 CR3: 000000002b1df000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5380 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5682 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_hrtimer_cancel include/trace/events/timer.h:290 [inline] debug_deactivate kernel/time/hrtimer.c:482 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0xaac/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 0a 41 05 f8 48 89 ef e8 52 b7 05 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 b3 6e f8 f7 65 8b 05 ec ca aa 76 85 c0 74 0a 5b 5d c3 e8 20 a5 RSP: 0018:ffffc900044f74d0 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1ff760e RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff906b34e0 R08: 0000000000000001 R09: ffffffff8ffa7977 R10: 0000000000000001 R11: 000000000000001f R12: 1ffffffff20d669b R13: 0000000000000000 R14: dead000000000100 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 free_pages_prepare mm/page_alloc.c:1357 [inline] free_pcp_prepare+0x2be/0xb60 mm/page_alloc.c:1403 free_unref_page_prepare mm/page_alloc.c:3324 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3403 release_pages+0x82a/0x1b30 mm/swap.c:956 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline] tlb_flush_mmu_free mm/mmu_gather.c:243 [inline] tlb_flush_mmu+0xe9/0x6b0 mm/mmu_gather.c:250 zap_pte_range mm/memory.c:1419 [inline] zap_pmd_range mm/memory.c:1468 [inline] zap_pud_range mm/memory.c:1497 [inline] zap_p4d_range mm/memory.c:1518 [inline] unmap_page_range+0x1ef7/0x35d0 mm/memory.c:1539 unmap_single_vma+0x198/0x310 mm/memory.c:1584 unmap_vmas+0x16b/0x2f0 mm/memory.c:1616 exit_mmap+0x201/0x670 mm/mmap.c:3179 __mmput+0x122/0x4b0 kernel/fork.c:1116 mmput+0x56/0x60 kernel/fork.c:1137 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2c20 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x34c/0x28b0 kernel/signal.c:2859 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f6a7234be99 Code: Unable to access opcode bytes at RIP 0x7f6a7234be6f. RSP: 002b:00007f6a70cc1218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6a7245ef68 RCX: 00007f6a7234be99 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6a7245ef68 RBP: 00007f6a7245ef60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a7245ef6c R13: 00007ffc290964ff R14: 00007f6a70cc1300 R15: 0000000000022000 task:kworker/u4:8 state:R running task stack:26632 pid:16364 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4d90 kernel/sched/core.c:6296 preempt_schedule_notrace+0x5b/0xd0 kernel/sched/core.c:6541 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36 rcu_read_unlock_sched_notrace include/linux/rcupdate.h:816 [inline] trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x458/0x510 kernel/locking/lockdep.c:5610 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:694 [inline] inet_twsk_purge+0x117/0x7d0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:595 process_one_work+0x9ac/0x1680 kernel/workqueue.c:2307 worker_thread+0x652/0x11c0 kernel/workqueue.c:2454 kthread+0x405/0x4f0 kernel/kthread.c:345 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10496 jiffies! g111633 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: task:rcu_preempt state:R running task stack:27872 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4d90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x405/0x4f0 kernel/kthread.c:345 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 16184 Comm: syz-executor.4 Not tainted 5.16.0-rc5-next-20211216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:458 print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:706 [inline] rcu_pending kernel/rcu/tree.c:3927 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2625 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x447/0xc90 kernel/smp.c:969 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 0b 74 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 95 06 00 00 8b 43 08 31 RSP: 0018:ffffc90004637d08 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff8880b9c41f60 RCX: ffffc9000a961000 RDX: 0000000000040000 RSI: ffffffff816c8d35 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816c8d5b R11: 0000000000000000 R12: ffffed10173883ed R13: 0000000000000000 R14: ffff8880b9c41f68 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] hardware_enable_all arch/x86/kvm/../../../virt/kvm/kvm_main.c:4901 [inline] kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1114 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4734 [inline] kvm_dev_ioctl+0x1546/0x1aa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4789 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fb0fa134e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb0f8aaa168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb0fa247f60 RCX: 00007fb0fa134e99 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003 RBP: 00007fb0fa18eff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd63f48d5f R14: 00007fb0f8aaa300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 53 push %rbx 1: 20 81 e2 ff 1f 00 and %al,0x1fffe2(%rcx) 7: 00 48 39 add %cl,0x39(%rax) a: d0 0f rorb (%rdi) c: 94 xchg %eax,%esp d: c0 48 83 c4 rorb $0xc4,-0x7d(%rax) 11: 08 0f or %cl,(%rdi) 13: b6 c0 mov $0xc0,%dh 15: 5b pop %rbx 16: c3 retq 17: 31 f6 xor %esi,%esi 19: e8 c5 fe ff ff callq 0xfffffee3 1e: 48 85 c0 test %rax,%rax 21: 75 b2 jne 0xffffffd5 23: 31 c0 xor %eax,%eax 25: 48 83 c4 08 add $0x8,%rsp 29: 5b pop %rbx * 2a: c3 retq <-- trapping instruction 2b: 48 83 c4 08 add $0x8,%rsp 2f: b8 01 00 00 00 mov $0x1,%eax 34: 5b pop %rbx 35: c3 retq 36: e8 c8 8e 90 fa callq 0xfa908f03 3b: 85 c0 test %eax,%eax 3d: 74 e4 je 0x23 3f: 8b .byte 0x8b