rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=ff7/1/0x4000000000000000 softirq=249660/249660 fqs=0 (t=10500 jiffies g=459129 q=61) rcu: rcu_preempt kthread starved for 10500 jiffies! g459129 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:28688 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 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: NMI backtrace for cpu 1 CPU: 1 PID: 24135 Comm: syz-executor.3 Not tainted 5.16.0-rc3-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:481 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x98/0x746 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: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+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:pie_calculate_probability+0x532/0x7c0 net/sched/sch_pie.c:412 Code: ef 45 0f b6 65 1a 4c 89 fe e8 fa 2a 1a fa 4c 39 fd 0f 86 d7 fe ff ff e8 7c 27 1a fa 48 8b 6b 20 31 ff 48 89 ee e8 fe 29 1a fa <48> 85 ed 0f 85 bb fe ff ff e8 60 27 1a fa 48 8d 6b 38 31 ff 44 89 RSP: 0000:ffffc9000c627b98 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880385d6e30 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8880a905ba00 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff875d8352 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888080020b00 R14: 0000000000000000 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+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7f4a0e7fc5b0 Code: 00 00 8b 07 85 c0 74 e2 c6 f8 ff eb cc 0f 1f 44 00 00 0f bf 06 8b 15 83 19 13 00 39 d0 74 ba 0f b7 d2 66 89 16 eb b2 0f 1f 00 <48> c7 c0 bc ff ff ff 64 48 03 04 25 00 00 00 00 c3 66 2e 0f 1f 84 RSP: 002b:00007f4a0d7be198 EFLAGS: 00000202 RAX: 00007f4a0e95bf60 RBX: 0000000000000005 RCX: 00007f4a0e8b0080 RDX: 0000000000021f3c RSI: 0000000000000004 RDI: 00007f4a0e8a1f4d RBP: 00007f4a0e8a2ff7 R08: 0000000000000bc1 R09: 00007fff49a6a080 R10: 00007fff49a6a090 R11: 0000000000091864 R12: 0000000000000000 R13: 00007f4a0ee8fb2f R14: 00007f4a0d7be300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 24135 Comm: syz-executor.3 Not tainted 5.16.0-rc3-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+0x9d/0x746 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: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+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:pie_calculate_probability+0x532/0x7c0 net/sched/sch_pie.c:412 Code: ef 45 0f b6 65 1a 4c 89 fe e8 fa 2a 1a fa 4c 39 fd 0f 86 d7 fe ff ff e8 7c 27 1a fa 48 8b 6b 20 31 ff 48 89 ee e8 fe 29 1a fa <48> 85 ed 0f 85 bb fe ff ff e8 60 27 1a fa 48 8d 6b 38 31 ff 44 89 RSP: 0000:ffffc9000c627b98 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880385d6e30 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8880a905ba00 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff875d8352 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888080020b00 R14: 0000000000000000 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+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7f4a0e7fc5b0 Code: 00 00 8b 07 85 c0 74 e2 c6 f8 ff eb cc 0f 1f 44 00 00 0f bf 06 8b 15 83 19 13 00 39 d0 74 ba 0f b7 d2 66 89 16 eb b2 0f 1f 00 <48> c7 c0 bc ff ff ff 64 48 03 04 25 00 00 00 00 c3 66 2e 0f 1f 84 RSP: 002b:00007f4a0d7be198 EFLAGS: 00000202 RAX: 00007f4a0e95bf60 RBX: 0000000000000005 RCX: 00007f4a0e8b0080 RDX: 0000000000021f3c RSI: 0000000000000004 RDI: 00007f4a0e8a1f4d RBP: 00007f4a0e8a2ff7 R08: 0000000000000bc1 R09: 00007fff49a6a080 R10: 00007fff49a6a090 R11: 0000000000091864 R12: 0000000000000000 R13: 00007f4a0ee8fb2f R14: 00007f4a0d7be300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: ef out %eax,(%dx) 1: 45 0f b6 65 1a movzbl 0x1a(%r13),%r12d 6: 4c 89 fe mov %r15,%rsi 9: e8 fa 2a 1a fa callq 0xfa1a2b08 e: 4c 39 fd cmp %r15,%rbp 11: 0f 86 d7 fe ff ff jbe 0xfffffeee 17: e8 7c 27 1a fa callq 0xfa1a2798 1c: 48 8b 6b 20 mov 0x20(%rbx),%rbp 20: 31 ff xor %edi,%edi 22: 48 89 ee mov %rbp,%rsi 25: e8 fe 29 1a fa callq 0xfa1a2a28 * 2a: 48 85 ed test %rbp,%rbp <-- trapping instruction 2d: 0f 85 bb fe ff ff jne 0xfffffeee 33: e8 60 27 1a fa callq 0xfa1a2798 38: 48 8d 6b 38 lea 0x38(%rbx),%rbp 3c: 31 ff xor %edi,%edi 3e: 44 rex.R 3f: 89 .byte 0x89