rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=122/1/0x4000000000000002 softirq=270767/270768 fqs=24 rcu: (t=10501 jiffies g=371393 q=143) rcu: rcu_preempt kthread starved for 10454 jiffies! g371393 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I25112 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803 rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948 rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 18115 Comm: syz-executor5 Not tainted 5.0.0-rc3+ #17 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1211 print_cpu_stall.cold+0x227/0x40c kernel/rcu/tree.c:1348 check_cpu_stall kernel/rcu/tree.c:1422 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks+0xb32/0x1380 kernel/rcu/tree.c:2521 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x50 kernel/kcov.c:106 Code: 65 8b 15 c8 ee 7f 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 <48> 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 RSP: 0018:ffff88808f50fb50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: dffffc0000000000 RCX: ffffc9001086c000 RDX: 000000000003ffff RSI: ffffffff86fd4dd8 RDI: 0000000000000004 RBP: ffff88808f50fb50 R08: ffff8880a8dfa480 R09: fffffbfff1480e9d R10: fffffbfff1480e9c R11: ffffffff8a4074e3 R12: ffff88809e1b0ec0 R13: 0000000000000001 R14: ffff8880a13a7840 R15: 0000000000000000 __x25_find_socket+0x48/0x120 net/x25/af_x25.c:327 x25_new_lci net/x25/af_x25.c:357 [inline] x25_connect+0x382/0x1050 net/x25/af_x25.c:786 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1c2bed7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1c2bed86d4 R13: 00000000004be5fe R14: 00000000004cec00 R15: 00000000ffffffff