rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=8e3/1/0x4000000000000000 softirq=57018/57018 fqs=378 (t=10502 jiffies g=100609 q=127) rcu: rcu_preempt kthread starved for 9747 jiffies! g100609 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:26576 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 schedule+0x12b/0x1f0 kernel/sched/core.c:6326 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1955 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2128 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 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: 0 Comm: swapper/0 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] RIP: 0010:acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline] RIP: 0010:acpi_idle_enter+0x42d/0x790 drivers/acpi/processor_idle.c:688 Code: fd 48 83 e3 08 44 8b 7c 24 04 0f 85 22 01 00 00 4c 8d 74 24 40 e8 83 55 0c fd eb 0c e8 9c b9 05 fd 0f 00 2d b5 fc 63 06 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 23 00 74 08 4c 89 f7 e8 9d 8b 51 fd RSP: 0018:ffffffff8c807ba0 EFLAGS: 00000286 RAX: 9c8628476f4b4d00 RBX: 0000000000000000 RCX: ffffffff90bb1903 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8c807c50 R08: ffffffff818b13b0 R09: fffffbfff19176d9 R10: fffffbfff19176d9 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880115b7064 R14: ffffffff8c807be0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2bc30000 CR3: 0000000013d98000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpuidle_enter_state+0x507/0xea0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e8/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403 start_kernel+0x4bf/0x56e init/main.c:1135 secondary_startup_64_no_verify+0xb1/0xbb NMI backtrace for cpu 1 CPU: 1 PID: 27647 Comm: syz-executor.4 Not tainted 5.16.0-rc1-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+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x22d/0x390 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+0x1e33/0x2bc0 kernel/rcu/tree.c:2597 update_process_times+0x197/0x200 kernel/time/timer.c:1785 tick_sched_handle kernel/time/tick-sched.c:226 [inline] tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:__output_copy kernel/events/internal.h:178 [inline] RIP: 0010:perf_output_read_group kernel/events/core.c:6928 [inline] RIP: 0010:perf_output_read+0x1150/0x1480 kernel/events/core.c:6961 Code: dd 4c 0f 43 eb 48 8b 44 24 20 42 80 3c 30 00 74 08 4c 89 e7 e8 61 b3 29 00 49 8b 3c 24 48 8b 74 24 48 4c 89 ea e8 b0 b5 29 00 <48> 8b 44 24 20 4c 89 f1 42 80 3c 30 00 74 0b 4c 89 e7 e8 39 b3 29 RSP: 0018:ffffc90003beec80 EFLAGS: 00000202 RAX: ffff88808c3c8650 RBX: 0000000000000010 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffc90003beed70 RDI: ffff88808c3c8660 RBP: ffffc90003beee10 R08: dffffc0000000000 R09: ffffed10118790cc R10: ffffed10118790cc R11: 0000000000000000 R12: ffffc90003bef128 R13: 0000000000000010 R14: dffffc0000000000 R15: ffffc90003bef118 perf_output_sample+0x338/0x23e0 kernel/events/core.c:7008 __perf_event_output kernel/events/core.c:7493 [inline] perf_event_output_forward+0x1e1/0x2c0 kernel/events/core.c:7507 __perf_event_overflow+0x1f8/0x380 kernel/events/core.c:9207 do_perf_sw_event kernel/events/core.c:9424 [inline] ___perf_sw_event+0x465/0x640 kernel/events/core.c:9455 __perf_sw_event+0x13f/0x270 kernel/events/core.c:9467 handle_mm_fault+0x21cc/0x2560 mm/memory.c:4798 do_user_addr_fault+0x8cc/0x10c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1485 [inline] exc_page_fault+0xa1/0x1e0 arch/x86/mm/fault.c:1541 asm_exc_page_fault+0x1e/0x30 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x30 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 0f 1f 80 00 00 00 00 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffffc90003bef8b8 EFLAGS: 00050206 RAX: ffffffff8413fa01 RBX: ffff8880354d8000 RCX: 0000000000007fcb RDX: 0000000000008000 RSI: 0000000020ee5000 RDI: ffff8880354d8035 RBP: ffffc90003befa10 R08: dffffc0000000000 R09: ffffed1006a9c000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008000 R13: 00007ffffffff000 R14: 0000000020ee4fcb R15: ffffc90003befe68 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin lib/iov_iter.c:168 [inline] _copy_from_iter+0x33c/0x1080 lib/iov_iter.c:767 copy_from_iter include/linux/uio.h:164 [inline] copy_from_iter_full include/linux/uio.h:170 [inline] skb_do_copy_data_nocache include/net/sock.h:2145 [inline] skb_copy_to_page_nocache include/net/sock.h:2171 [inline] tcp_sendmsg_locked+0x1bed/0x48a0 net/ipv4/tcp.c:1334 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] __sys_sendto+0x42e/0x5b0 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd4df177ae9 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:00007fd4dc6ed188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fd4df28af60 RCX: 00007fd4df177ae9 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 000000000000000a RBP: 00007fd4df1d1f6d R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe036a8edf R14: 00007fd4dc6ed300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: fd std 1: 48 83 e3 08 and $0x8,%rbx 5: 44 8b 7c 24 04 mov 0x4(%rsp),%r15d a: 0f 85 22 01 00 00 jne 0x132 10: 4c 8d 74 24 40 lea 0x40(%rsp),%r14 15: e8 83 55 0c fd callq 0xfd0c559d 1a: eb 0c jmp 0x28 1c: e8 9c b9 05 fd callq 0xfd05b9bd 21: 0f 00 2d b5 fc 63 06 verw 0x663fcb5(%rip) # 0x663fcdd 28: fb sti 29: f4 hlt * 2a: 4c 89 f3 mov %r14,%rbx <-- trapping instruction 2d: 48 c1 eb 03 shr $0x3,%rbx 31: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) 36: 74 08 je 0x40 38: 4c 89 f7 mov %r14,%rdi 3b: e8 9d 8b 51 fd callq 0xfd518bdd