rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=57a/1/0x4000000000000000 softirq=22878/22880 fqs=81 (t=10500 jiffies g=39413 q=544) rcu: rcu_preempt kthread starved for 10326 jiffies! g39413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29080 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 1 CPU: 1 PID: 13192 Comm: syz-executor.3 Not tainted 5.9.0-rc1-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_release+0x48c/0x8e0 kernel/locking/lockdep.c:5026 Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 7f 03 00 00 48 83 3d b8 cf 5b 08 00 0f 84 a9 01 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c5 48 c7 45 00 RSP: 0018:ffffc9001789ece8 EFLAGS: 00000282 RAX: 1ffffffff136c6c1 RBX: ffff8880a686a2c0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff89bd6340 RDI: 0000000000000282 RBP: 1ffff92002f13d9f R08: 0000000000000001 R09: ffff8880a686aba0 R10: fffffbfff1564359 R11: 0000000000000001 R12: 0000000000000003 R13: ffffffff87b4ccc1 R14: 0000000000000004 R15: ffff8880a686a2c0 rcu_lock_release include/linux/rcupdate.h:246 [inline] rcu_read_unlock include/linux/rcupdate.h:688 [inline] tipc_sk_lookup+0x5e3/0xa80 net/tipc/socket.c:2972 tipc_sk_rcv+0x27a/0x1ec0 net/tipc/socket.c:2459 tipc_node_xmit+0x2b0/0xce0 net/tipc/node.c:1655 tipc_node_xmit_skb+0xd5/0x140 net/tipc/node.c:1715 tipc_sk_rcv+0x1754/0x1ec0 net/tipc/socket.c:2489 tipc_node_xmit+0x2b0/0xce0 net/tipc/node.c:1655 tipc_sk_push_backlog+0x324/0x790 net/tipc/socket.c:1302 tipc_sk_filter_connect net/tipc/socket.c:2224 [inline] tipc_sk_filter_rcv+0xafe/0x3250 net/tipc/socket.c:2333 tipc_sk_enqueue net/tipc/socket.c:2413 [inline] tipc_sk_rcv+0xd1a/0x1ec0 net/tipc/socket.c:2464 tipc_node_xmit+0x2b0/0xce0 net/tipc/node.c:1655 tipc_node_xmit_skb net/tipc/node.c:1715 [inline] tipc_node_distr_xmit+0x15c/0x3a0 net/tipc/node.c:1730 tipc_sk_backlog_rcv+0x155/0x1c0 net/tipc/socket.c:2381 sk_backlog_rcv include/net/sock.h:1011 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2542 release_sock+0x54/0x1b0 net/core/sock.c:3065 tipc_release+0xbb1/0x1a70 net/tipc/socket.c:638 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9519dbbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000021 RAX: 0000000000000004 RBX: 00000000000029c0 RCX: 000000000045d4d9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 00007f9519dbbca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff998541ff R14: 00007f9519dbc9c0 R15: 000000000118cfec