rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=57a/1/0x4000000000000002 softirq=11495/11505 fqs=19 (t=10500 jiffies g=6213 q=60) rcu: rcu_preempt kthread starved for 10457 jiffies! g6213 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 8181 Comm: syz-executor.2 Not tainted 5.4.0-syzkaller #0 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+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:free_thread_stack+0x18b/0x590 kernel/fork.c:284 Code: ff ff e8 28 04 00 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 09 a4 69 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 df e8 eb a3 69 00 48 8b 1b e9 82 ff ff ff e8 de 2c 2e RSP: 0018:ffffc90002056e28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff11012744881 RBX: ffff888093a24408 RCX: ffff888095024500 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00024aaa80 RBP: ffffc90002056e60 R08: 000000000003a768 R09: ffffed10151eaec7 R10: ffffed10151eaec7 R11: 0000000000000000 R12: ffff888093a244a0 R13: dffffc0000000000 R14: 1ffff11012744894 R15: ffff8880a8f57628 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:kfree+0x1a3/0x200 mm/slab.c:3758 Code: 48 83 3d 67 19 59 07 00 74 68 4c 89 f7 57 9d 0f 1f 44 00 00 eb 19 e8 ec b7 ca ff 48 83 3d 4c 19 59 07 00 74 51 4c 89 f7 57 9d <0f> 1f 44 00 00 5b 41 5c 41 5e 41 5f 5d c3 48 ff c9 48 89 c8 e9 c8 RSP: 0018:ffffc90002057070 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: ffff888095024d94 RBX: ffff8880aa800a80 RCX: ffffffff815c0597 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffffc90002057090 R08: ffff888095024d58 R09: fffffbfff13c8524 R10: fffffbfff13c8524 R11: 0000000000000000 R12: ffff88809689d800 R13: 0000000000000000 R14: 0000000000000286 R15: ffffffff86380c36 skb_free_head net/core/skbuff.c:591 [inline] skb_release_data+0x726/0x8c0 net/core/skbuff.c:611 skb_release_all net/core/skbuff.c:665 [inline] __kfree_skb+0x59/0x1c0 net/core/skbuff.c:679 consume_skb+0x72/0x110 net/core/skbuff.c:838 netlink_broadcast_filtered+0x1056/0x1170 net/netlink/af_netlink.c:1512 netlink_broadcast net/netlink/af_netlink.c:1534 [inline] nlmsg_multicast include/net/netlink.h:968 [inline] nlmsg_notify+0xfc/0x1f0 net/netlink/af_netlink.c:2520 rtnl_notify+0x9b/0xc0 net/core/rtnetlink.c:737 rtmsg_fib+0x631/0x9c0 net/ipv4/fib_semantics.c:524 fib_table_insert+0x1902/0x1f10 net/ipv4/fib_trie.c:1285 fib_magic+0x438/0x5e0 net/ipv4/fib_frontend.c:1082 fib_add_ifaddr+0x150/0x590 net/ipv4/fib_frontend.c:1104 fib_inetaddr_event+0x15d/0x320 net/ipv4/fib_frontend.c:1417 notifier_call_chain kernel/notifier.c:95 [inline] __blocking_notifier_call_chain+0x191/0x260 kernel/notifier.c:319 blocking_notifier_call_chain+0x2d/0x40 kernel/notifier.c:330 __inet_insert_ifa+0x96b/0xb60 net/ipv4/devinet.c:552 inet_rtm_newaddr+0x104b/0x1980 net/ipv4/devinet.c:951 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5422 netlink_rcv_skb+0x19e/0x3d0 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5440 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x767/0x920 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa21/0xd40 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] __sys_sendto+0x442/0x5e0 net/socket.c:1985 __do_sys_sendto net/socket.c:1997 [inline] __se_sys_sendto net/socket.c:1993 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:1993 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414373 Code: ff 0f 83 b0 19 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d fd 40 66 00 00 75 17 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 81 19 00 00 c3 48 83 ec 08 e8 87 fa ff ff RSP: 002b:00007ffea10b81d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000a72200 RCX: 0000000000414373 RDX: 0000000000000028 RSI: 0000000000a72250 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffea10b81e0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000a72250 R15: 0000000000000003