rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10451 ticks this GP) idle=1df/1/0x4000000000000000 softirq=263172/263172 fqs=37 (t=10500 jiffies g=437345 q=1354) rcu: rcu_preempt kthread timer wakeup didn't happen for 10421 jiffies! g437345 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=157873 rcu: rcu_preempt kthread starved for 10422 jiffies! g437345 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:28696 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: 4096 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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 a3 36 4a 00 eb 07 0f 00 2d 6a 98 55 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 66 31 4a 00 8b 74 24 0c RSP: 0018:ffffc9000514f8c0 EFLAGS: 00000206 RAX: 000000000000aad2 RBX: 0000000000000000 RCX: 1ffffffff1fb079e RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffff88802a9e2388 R08: 0000000000000001 R09: ffffffff8fd38ac7 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffffed100553c471 R14: 0000000000000001 R15: ffff8880b9c3a880 FS: 00007f5efde38700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d47781000 CR3: 0000000089b4b000 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:355 [inline] lock_sock_nested+0x5b/0xf0 net/core/sock.c:3288 sctp_close+0xbc/0x930 net/sctp/socket.c:1490 inet_release+0x12e/0x280 net/ipv4/af_inet.c:427 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:479 __sock_release+0xcd/0x280 net/socket.c:649 sock_close+0x18/0x20 net/socket.c:1314 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 get_signal+0x1b80/0x21d0 kernel/signal.c:2628 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5f008e3ae9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5efde38188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000010000 RBX: 00007f5f009f7020 RCX: 00007f5f008e3ae9 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000006 RBP: 00007f5f0093df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000032f0b R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd5b24c4ff R14: 00007f5efde38300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c: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:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2d/0x60 kernel/kcov.c:197 Code: 69 fd 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 a4 15 00 00 <85> c0 74 2b 8b 82 80 15 00 00 83 f8 02 75 20 48 8b 8a 88 15 00 00 RSP: 0018:ffffc90000d97788 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff888146d20000 RCX: 0000000000000100 RDX: ffff888011995700 RSI: ffffffff885f8d2f RDI: 0000000000000003 RBP: ffff888146d2013a R08: 000000000000000f R09: 0000000000000500 R10: ffffffff885f8d20 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000500 R14: 0000000000000000 R15: ffff888146d20048 __sctp_auth_cid+0x6f/0x160 net/sctp/auth.c:647 sctp_auth_recv_cid+0x6f/0xa0 net/sctp/auth.c:694 sctp_assoc_bh_rcv+0x1b1/0x6c0 net/sctp/associola.c:1035 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80 sctp_rcv+0xfe3/0x3290 net/sctp/input.c:256 sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5462 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5576 process_backlog+0x2a5/0x6c0 net/core/dev.c:6452 __napi_poll+0xaf/0x440 net/core/dev.c:7017 napi_poll net/core/dev.c:7084 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7171 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:920 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 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 a3 36 4a 00 callq 0x4a36c2 1f: eb 07 jmp 0x28 21: 0f 00 2d 6a 98 55 08 verw 0x855986a(%rip) # 0x8559892 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 66 31 4a 00 callq 0x4a31a2 3c: 8b 74 24 0c mov 0xc(%rsp),%esi