rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=301/1/0x4000000000000000 softirq=226614/226616 fqs=1 (t=10500 jiffies g=416801 q=74) rcu: rcu_preempt kthread timer wakeup didn't happen for 10496 jiffies! g416801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=130252 rcu: rcu_preempt kthread starved for 10497 jiffies! g416801 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:28616 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 31240 Comm: kworker/u4:14 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_rcv tipc_conn_recv_work RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:894 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 93 53 4a 00 eb 07 0f 00 2d aa 5b 55 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 4e 4a 00 8b 74 24 0c RSP: 0018:ffffc9000452fb08 EFLAGS: 00000202 RAX: 0000000002c88ec8 RBX: 0000000000000000 RCX: 1ffffffff1fb758e RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffff88803f52d458 R08: 0000000000000001 R09: ffffffff8fd5baff R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed1007ea5a8b R14: 0000000000000001 R15: ffff8880b9c3a880 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fca0a18160 CR3: 000000006f290000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:597 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:354 [inline] tipc_conn_kref_release+0x47/0x380 net/tipc/topsrv.c:129 kref_put include/linux/kref.h:65 [inline] conn_put net/tipc/topsrv.c:147 [inline] tipc_conn_recv_work+0x14a/0x190 net/tipc/topsrv.c:430 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 1 CPU: 1 PID: 4159 Comm: kworker/u4:0 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:199 Code: 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 89 a9 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 <65> 48 8b 14 25 40 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 RSP: 0018:ffffc900042d7bc8 EFLAGS: 00000246 RAX: 0000000000000201 RBX: 000000007dcab8eb RCX: 0000000000000000 RDX: 1ffff11007ea5a8a RSI: ffffffff83f6269e RDI: ffff88803f52d400 RBP: ffff88803f52d400 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88b17219 R11: 0000000000000000 R12: 000000007dcab8eb R13: ffffed1007ea5a93 R14: ffff88802b1d4800 R15: 0000000000000001 radix_tree_lookup+0xe/0x20 lib/radix-tree.c:817 tipc_topsrv_stop net/tipc/topsrv.c:691 [inline] tipc_topsrv_exit_net+0x20a/0x5d0 net/tipc/topsrv.c:715 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: fa cli 1: 83 e2 07 and $0x7,%edx 4: 38 d0 cmp %dl,%al 6: 7f 04 jg 0xc 8: 84 c0 test %al,%al a: 75 63 jne 0x6f c: 0f b6 07 movzbl (%rdi),%eax f: 40 38 c6 cmp %al,%sil 12: 74 35 je 0x49 14: 48 83 c4 10 add $0x10,%rsp 18: c3 retq 19: c3 retq 1a: e8 93 53 4a 00 callq 0x4a53b2 1f: eb 07 jmp 0x28 21: 0f 00 2d aa 5b 55 08 verw 0x8555baa(%rip) # 0x8555bd2 28: fb sti 29: f4 hlt * 2a: 48 83 c4 10 add $0x10,%rsp <-- trapping instruction 2e: c3 retq 2f: 89 74 24 0c mov %esi,0xc(%rsp) 33: 48 89 3c 24 mov %rdi,(%rsp) 37: e8 56 4e 4a 00 callq 0x4a4e92 3c: 8b 74 24 0c mov 0xc(%rsp),%esi