rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=9a6/1/0x4000000000000002 softirq=95441/95441 fqs=0 rcu: (t=10500 jiffies g=134577 q=209) rcu: rcu_preempt kthread starved for 10500 jiffies! g134577 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29024 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803 rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline] rcu_gp_kthread+0x956/0x17a0 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: 17347 Comm: syz-executor.0 Not tainted 5.0.0-rc5+ #54 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+0x172/0x1f0 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 kernel/rcu/tree.c:1348 [inline] check_cpu_stall kernel/rcu/tree.c:1422 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks.cold+0x500/0xa4a 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+0x33e/0xde0 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+0x120/0x570 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:__x25_find_socket+0x58/0x120 net/x25/af_x25.c:327 Code: 83 ec 68 0f 84 b0 00 00 00 48 bb 00 00 00 00 00 fc ff df eb 30 e8 28 60 3d fb 49 8d 7c 24 68 48 89 f8 48 c1 e8 03 80 3c 18 00 <0f> 85 a6 00 00 00 4d 8b 64 24 68 4d 85 e4 74 7f e8 03 60 3d fb 49 RSP: 0018:ffff888098af7c58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff110123f0d2d RBX: dffffc0000000000 RCX: ffffc900063ee000 RDX: 0000000000040000 RSI: ffffffff86327de8 RDI: ffff888091f86968 RBP: ffff888098af7c80 R08: ffff88805fdfa5c0 R09: fffffbfff12827e5 R10: fffffbfff12827e4 R11: ffffffff89413f23 R12: ffff888091f86900 R13: 0000000000000001 R14: ffff88809e4be480 R15: 0000000000000000 x25_new_lci net/x25/af_x25.c:357 [inline] x25_connect+0x374/0xdf0 net/x25/af_x25.c:786 __sys_connect+0x266/0x330 net/socket.c:1684 __do_sys_connect net/socket.c:1695 [inline] __se_sys_connect net/socket.c:1692 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1692 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f54f12e7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000000000012 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000073c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f54f12e86d4 R13: 00000000004be378 R14: 00000000004ceae0 R15: 00000000ffffffff