rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=5f5/1/0x4000000000000000 softirq=6317/6318 fqs=498 (t=10500 jiffies g=6053 q=695 ncpus=2) rcu: rcu_preempt kthread starved for 9319 jiffies! g6053 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:29264 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5106 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421 schedule+0xd2/0x1f0 kernel/sched/core.c:6493 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1907 rcu_gp_fqs_loop+0x1c0/0x840 kernel/rcu/tree.c:2078 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2267 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:116 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:559 NMI backtrace for cpu 1 CPU: 1 PID: 3798 Comm: syz-executor.3 Not tainted 5.18.0-rc3-next-20220422-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+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:369 print_cpu_stall kernel/rcu/tree_stall.h:665 [inline] check_cpu_stall kernel/rcu/tree_stall.h:749 [inline] rcu_pending kernel/rcu/tree.c:4068 [inline] rcu_sched_clock_irq.cold+0x144/0x8fc kernel/rcu/tree.c:2755 update_process_times+0x16d/0x200 kernel/time/timer.c:1811 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473 __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:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c RSP: 0018:ffffc90000de0608 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199 RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd RBP: ffff88802334e1c8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81807158 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed1004669c39 R14: 0000000000000001 R15: ffff8880b9d3ae40 pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8c7/0xb50 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:354 [inline] task_lock include/linux/sched/task.h:170 [inline] __get_task_comm+0x23/0x50 fs/exec.c:1219 __set_page_owner_handle mm/page_owner.c:174 [inline] __set_page_owner+0x253/0x380 mm/page_owner.c:192 prep_new_page mm/page_alloc.c:2394 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] kmem_cache_alloc_node+0x122/0x3f0 mm/slub.c:3264 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1337 [inline] wg_packet_send_keepalive+0x6e/0x300 drivers/net/wireguard/send.c:226 wg_expired_send_persistent_keepalive+0x5a/0x70 drivers/net/wireguard/timers.c:141 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444 expire_timers kernel/time/timer.c:1489 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760 __run_timers kernel/time/timer.c:1738 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 ac 15 00 00 85 c0 74 2b 8b 82 88 15 00 00 <83> f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 48 RSP: 0018:ffffc900044371d8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88802334d880 RSI: ffffffff83faa507 RDI: ffff888012f616f8 RBP: ffff888012f616e8 R08: 0000000000000001 R09: ffff888012f616f7 R10: ffffed10025ec2de R11: 0000000000000001 R12: 000000000000000e R13: 0000000000000010 R14: ffff888012f616c8 R15: 0000000000000007 strscpy_pad+0x67/0x70 lib/string_helpers.c:794 __get_task_comm+0x35/0x50 fs/exec.c:1221 __set_page_owner_handle mm/page_owner.c:174 [inline] __set_page_owner+0x253/0x380 mm/page_owner.c:192 prep_new_page mm/page_alloc.c:2394 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356 alloc_pages_vma+0xf9/0x770 mm/mempolicy.c:2221 wp_page_copy+0xaef/0x1e20 mm/memory.c:3100 do_wp_page+0x573/0x1b60 mm/memory.c:3397 handle_pte_fault mm/memory.c:4922 [inline] __handle_mm_fault+0x1fe6/0x33d0 mm/memory.c:5043 handle_mm_fault+0x1c8/0x790 mm/memory.c:5141 do_user_addr_fault+0x489/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1484 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1540 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166 Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 a4 31 c0 0f 01 ca c3 89 ca eb 0a 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90004437a10 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000001000 RSI: ffff88800f243180 RDI: 000000002039d000 RBP: 000000002039ce80 R08: 0000000000000000 R09: ffff88800f243fff R10: ffffed1001e487ff R11: 0000000000000000 R12: ffff88800f243000 R13: 00007fffffffe000 R14: 0000000000000000 R15: ffffc90004437d18 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout.part.0+0xd8/0x100 lib/iov_iter.c:155 copyout lib/iov_iter.c:189 [inline] copy_page_to_iter_iovec lib/iov_iter.c:226 [inline] __copy_page_to_iter lib/iov_iter.c:852 [inline] copy_page_to_iter+0x49f/0x1170 lib/iov_iter.c:880 process_vm_rw_pages mm/process_vm_access.c:45 [inline] process_vm_rw_single_vec mm/process_vm_access.c:117 [inline] process_vm_rw_core.constprop.0+0x5cd/0x990 mm/process_vm_access.c:215 process_vm_rw+0x29c/0x300 mm/process_vm_access.c:283 __do_sys_process_vm_readv mm/process_vm_access.c:295 [inline] __se_sys_process_vm_readv mm/process_vm_access.c:291 [inline] __x64_sys_process_vm_readv+0xdf/0x1b0 mm/process_vm_access.c:291 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: 0033:0x7fa4602890e9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa46137e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007fa46039bf60 RCX: 00007fa4602890e9 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 000000000000000c RBP: 00007fa4602e308d R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff5710c5ff R14: 00007fa46137e300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: fa cli 1: 83 e2 07 and $0x7,%edx 4: 38 d0 cmp %dl,%al 6: 7f 04 jg 0xc 8: 84 c0 test %al,%al a: 75 63 jne 0x6f c: 0f b6 07 movzbl (%rdi),%eax f: 40 38 c6 cmp %al,%sil 12: 74 35 je 0x49 14: 48 83 c4 10 add $0x10,%rsp 18: c3 retq 19: c3 retq 1a: e8 23 91 4b 00 callq 0x4b9142 1f: eb 07 jmp 0x28 21: 0f 00 2d da b1 94 08 verw 0x894b1da(%rip) # 0x894b202 28: fb sti 29: f4 hlt * 2a: 48 83 c4 10 add $0x10,%rsp <-- trapping instruction 2e: c3 retq 2f: 89 74 24 0c mov %esi,0xc(%rsp) 33: 48 89 3c 24 mov %rdi,(%rsp) 37: e8 56 8f 4b 00 callq 0x4b8f92 3c: 8b 74 24 0c mov 0xc(%rsp),%esi