rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=465/1/0x4000000000000000 softirq=195268/195269 fqs=6 (t=10500 jiffies g=278009 q=275) rcu: rcu_preempt kthread starved for 10487 jiffies! g278009 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:29152 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18826 Comm: kworker/u4:8 Not tainted 5.14.0-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 40 4c 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:ffffc900193479f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c38900 RCX: 0000000000000000 RDX: ffff8880201f1c80 RSI: ffffffff816ad500 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816ad526 R11: 0000000000000000 R12: ffffed1017387121 R13: 0000000000000000 R14: ffff8880b9c38908 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000540198 CR3: 000000000b68e000 CR4: 00000000001506e0 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:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 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:623 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:615 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 0 CPU: 0 PID: 2962 Comm: syz-executor.5 Not tainted 5.14.0-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:105 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 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:1421 __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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:128 [inline] RIP: 0010:pie_calculate_probability+0x27d/0x7c0 net/sched/sch_pie.c:348 Code: 89 c6 4c 89 6c 24 38 e8 31 d9 24 fa 47 8d 24 a4 31 d2 4c 89 ff 43 8d 0c 24 48 c1 ed 02 48 b8 ff ff ff ff ff ff ff 00 48 f7 f1 <49> 89 c5 48 89 c6 48 c1 eb 02 49 89 cc e8 d1 de 24 fa 4d 39 ef 73 RSP: 0018:ffffc90000007c50 EFLAGS: 00000203 RAX: 000000a7c5ac471b RBX: 000000000abcc771 RCX: 00000000000186a0 RDX: 0000000000006d1f RSI: ffffffff8751480f RDI: 0000000000000000 RBP: 000000000044b82f R08: 00000000000f4240 R09: 0000000000000000 R10: ffffffff87514856 R11: 0000000000000000 R12: 000000000000c350 R13: 0000068db8bac710 R14: 0000000000000003 R15: 0000000000000000 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:kmem_cache_alloc_trace+0x1fb/0x3c0 mm/slub.c:2988 Code: 8b 4d 18 45 89 e8 4c 89 f2 4c 89 e6 48 8b 7c 24 40 e8 c9 91 ff ff 48 8b 44 24 08 65 48 2b 04 25 28 00 00 00 0f 85 be 01 00 00 <48> 83 c4 10 44 89 e9 4c 89 f2 5b 4c 89 e6 48 89 ef 5d 41 5c 41 5d RSP: 0018:ffffc9001adf7ba0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000080 RDX: 0000000000000028 RSI: ffff88808f9fa880 RDI: ffffffff814ef478 RBP: ffff888010c41640 R08: 0000000000000cc0 R09: ffff88808f9fa880 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808f9fa880 R13: 0000000000000cc0 R14: 0000000000000028 R15: 0000000000000cc0 kmalloc include/linux/slab.h:591 [inline] call_modprobe kernel/kmod.c:79 [inline] __request_module+0x2f8/0xa60 kernel/kmod.c:170 inet6_create net/ipv6/af_inet6.c:164 [inline] inet6_create+0xadf/0x1030 net/ipv6/af_inet6.c:111 __sock_create+0x353/0x790 net/socket.c:1464 sock_create net/socket.c:1515 [inline] __sys_socket+0xef/0x200 net/socket.c:1557 __do_sys_socket net/socket.c:1566 [inline] __se_sys_socket net/socket.c:1564 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1564 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: 0033:0x4665f9 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:00007f5a316ce188 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 8010000000000084 RSI: 0000000000000000 RDI: 000000000000000a RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 0000000000a9fb1f R14: 00007f5a316ce300 R15: 0000000000022000 ---------------- 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 40 4c 0b 00 callq 0xb4c68 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