INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=842/140000000000002/0 softirq=11824/11841 fqs=7 (t=10500 jiffies g=1923 c=1922 q=1756) rcu_preempt kthread starved for 10485 jiffies! g1923 c1922 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29920 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 7873 Comm: syz-executor.5 Not tainted 4.14.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:ip_vs_local_request6+0x0/0x30 net/netfilter/ipvs/ip_vs_core.c:2044 RSP: 0018:ffff8880aeb07a60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: ffff888092a90e48 RBX: ffff888092a90e00 RCX: ffffffff8540be90 RDX: ffff8880aeb07af0 RSI: ffff88808ccac5c0 RDI: 0000000000000000 RBP: 0000000000000004 R08: 0000000000000001 R09: ffff8880aeb07b10 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808ccac5c0 R13: ffff8880aeb07af0 R14: dffffc0000000000 R15: ffffed10125521c0 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xa5/0x1a0 net/netfilter/core.c:467 nf_hook.constprop.0+0x15e/0x290 include/linux/netfilter.h:205 NF_HOOK include/linux/netfilter.h:248 [inline] ndisc_send_skb+0x83b/0x11e0 net/ipv6/ndisc.c:483 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677 addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3757 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:__sanitizer_cov_trace_pc+0x29/0x50 kernel/kcov.c:71 RSP: 0018:ffff888065ea7950 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: ffff88808d1dc0c0 RBX: ffff8880a1295540 RCX: ffffc90005e14000 RDX: 0000000000000001 RSI: ffffffff86e453c0 RDI: ffffffff86e45400 RBP: ffffffff86e45400 R08: 0000000000000000 R09: 0000000000020012 R10: ffff88808d1dc968 R11: ffff88808d1dc0c0 R12: ffff88821ac49940 R13: ffffffff86e453c0 R14: 1ffff1100cbd4f41 R15: ffff88821ac48040 check_preemption_disabled+0x15/0x240 lib/smp_processor_id.c:14 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:360 [inline] rcu_is_watching+0x11/0xb0 kernel/rcu/tree.c:1130 rcu_read_lock_held+0x7c/0xc0 kernel/rcu/update.c:328 __rhashtable_insert_fast include/linux/rhashtable.h:727 [inline] rhashtable_lookup_insert_key include/linux/rhashtable.h:982 [inline] __netlink_insert net/netlink/af_netlink.c:489 [inline] netlink_insert+0x9ef/0xe60 net/netlink/af_netlink.c:553 netlink_autobind.isra.0+0x1a5/0x290 net/netlink/af_netlink.c:813 netlink_sendmsg+0x820/0xbe0 net/netlink/af_netlink.c:1840 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c479 RSP: 002b:00007f266c8aec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f266c8af6d4 RCX: 000000000045c479 RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000007 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009f2 R14: 00000000004cc6a7 R15: 000000000076bf2c INFO: rcu_sched detected stalls on CPUs/tasks: 1-...: (1 GPs behind) idle=842/140000000000001/0 softirq=11840/11841 fqs=6 (detected by 0, t=10558 jiffies, g=1326, c=1325, q=3) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2357 Comm: kworker/u4:4 Not tainted 4.14.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a168a180 task.stack: ffff8880a1748000 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline] RIP: 0010:__lock_acquire+0x899/0x4620 kernel/locking/lockdep.c:3362 RSP: 0018:ffff8880a174fae0 EFLAGS: 00000086 RAX: 0000000000000086 RBX: 0000000000000000 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff87d843e0 RBP: ffff8880a174fc88 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8880a168a180 R12: ffffffff87d843e0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001c327d8 CR3: 000000008f521000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:629 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x103/0x6d0 net/batman-adv/network-coding.c:726 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 67 d1 87 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 68 2c 00 00 48 83 3d 7f 87 8b 06 00 0f 84 27 09 00 00 9c 58 <0f> 1f 44 00 00 f6 c4 02 0f 84 60 f8 ff ff e8 44 da b4 01 85 c0 rcu_sched kthread starved for 10545 jiffies! g1326 c1325 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_sched R running task 29984 9 2 0x80000000 Call Trace: preempt_schedule_common+0x4a/0xc0 kernel/sched/core.c:3508 ___preempt_schedule+0x16/0x18 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xb7/0xe0 kernel/locking/spinlock.c:192 force_qs_rnp+0xbf/0x4f0 kernel/rcu/tree.c:2854 rcu_gp_fqs kernel/rcu/tree.c:2117 [inline] rcu_gp_kthread+0xe02/0x1ce0 kernel/rcu/tree.c:2269 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404