rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=68b/1/0x4000000000000000 softirq=32507/32509 fqs=0 (t=10659 jiffies g=46169 q=284) rcu: rcu_preempt kthread starved for 10659 jiffies! g46169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28736 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 973 Comm: kworker/u4:4 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 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 90 7a 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90004b3f9f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d3fca0 RCX: 0000000000000000 RDX: ffff88801b063a00 RSI: ffffffff816bfc60 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816bfc86 R11: 0000000000000000 R12: ffffed10173a7f95 R13: 0000000000000001 R14: ffff8880b9d3fca8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f9f0b3000 CR3: 000000000b88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1112 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1297 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline] text_poke_flush arch/x86/kernel/alternative.c:1448 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1da/0x400 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:734 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:726 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 1 CPU: 1 PID: 3630 Comm: syz-executor.1 Not tainted 5.16.0-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_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2597 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:__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 4a 03 11 f8 48 89 ef e8 02 79 11 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 43 43 04 f8 65 8b 05 cc e8 b6 76 85 c0 74 0a 5b 5d c3 e8 90 2f RSP: 0018:ffffc9000289fb68 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1ff5ea6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff888076798150 R08: 0000000000000001 R09: ffffffff8ffa2a27 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888076798150 R13: ffff888076798198 R14: ffff888076798198 R15: ffff888076798198 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] ref_tracker_dir_exit.cold+0x137/0x1e3 lib/ref_tracker.c:37 __put_net+0x15/0x70 net/core/net_namespace.c:640 put_net include/net/net_namespace.h:268 [inline] put_net_track include/net/net_namespace.h:342 [inline] __sk_destruct+0x6d2/0x920 net/core/sock.c:2042 sk_destruct+0xbd/0xe0 net/core/sock.c:2058 __sk_free+0xef/0x3d0 net/core/sock.c:2069 sk_free+0x78/0xa0 net/core/sock.c:2080 sock_put include/net/sock.h:1912 [inline] __tun_detach+0xdb4/0x13e0 drivers/net/tun.c:681 tun_detach drivers/net/tun.c:693 [inline] tun_chr_close+0x15c/0x180 drivers/net/tun.c:3405 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xc14/0x2b40 kernel/exit.c:832 do_group_exit+0x125/0x310 kernel/exit.c:929 __do_sys_exit_group kernel/exit.c:940 [inline] __se_sys_exit_group kernel/exit.c:938 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:938 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: 0033:0x7f009daa7fe9 Code: Unable to access opcode bytes at RIP 0x7f009daa7fbf. RSP: 002b:00007fffc59e7468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fffc59e7610 RCX: 00007f009daa7fe9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000025 R09: 00007fffc59e7610 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f009db0205e R13: 000000000000001c R14: 0000000000000008 R15: 00007fffc59e7650 ---------------- Code disassembly (best guess): 0: 0b 00 or (%rax),%eax 2: 85 ed test %ebp,%ebp 4: 74 4d je 0x53 6: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax d: fc ff df 10: 4d 89 f4 mov %r14,%r12 13: 4c 89 f5 mov %r14,%rbp 16: 49 c1 ec 03 shr $0x3,%r12 1a: 83 e5 07 and $0x7,%ebp 1d: 49 01 c4 add %rax,%r12 20: 83 c5 03 add $0x3,%ebp 23: e8 90 7a 0b 00 callq 0xb7ab8 28: f3 90 pause * 2a: 41 0f b6 04 24 movzbl (%r12),%eax <-- trapping instruction 2f: 40 38 c5 cmp %al,%bpl 32: 7c 08 jl 0x3c 34: 84 c0 test %al,%al 36: 0f 85 33 06 00 00 jne 0x66f 3c: 8b 43 08 mov 0x8(%rbx),%eax 3f: 31 .byte 0x31