rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=f82/1/0x4000000000000000 softirq=50465/50466 fqs=43 (t=10502 jiffies g=82517 q=235) rcu: rcu_preempt kthread timer wakeup didn't happen for 10416 jiffies! g82517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=48927 rcu: rcu_preempt kthread starved for 10419 jiffies! g82517 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:29096 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4695 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:6026 schedule+0xd3/0x270 kernel/sched/core.c:6105 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 kernel/kthread.c:319 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: 19734 Comm: syz-executor.3 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:90 [inline] RIP: 0010:kvm_wait arch/x86/kernel/kvm.c:888 [inline] RIP: 0010:kvm_wait+0xaf/0xf0 arch/x86/kernel/kvm.c:871 Code: 10 c3 c3 89 74 24 0c 48 89 3c 24 e8 4b dd 47 00 8b 74 24 0c 48 8b 3c 24 eb 82 e8 5c e2 47 00 eb 07 0f 00 2d c3 c5 55 08 fb f4 9b eb 07 0f 00 2d b6 c5 55 08 f4 eb c5 89 74 24 0c 48 89 3c 24 RSP: 0018:ffffc90001f275e8 EFLAGS: 00000212 RAX: 000000000000a3e0 RBX: 0000000000000000 RCX: 1ffffffff1fa5de2 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffff88808cc700f0 R08: 0000000000000001 R09: ffffffff8fcdb9bf R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffffed101198e01e R14: 0000000000000001 R15: ffff8880b9c52a00 FS: 00007f0ee4eeb700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0ee4ea9718 CR3: 0000000017194000 CR4: 00000000001506f0 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:113 spin_lock include/linux/spinlock.h:354 [inline] __dev_xmit_skb net/core/dev.c:3913 [inline] __dev_queue_xmit+0x1d1f/0x3620 net/core/dev.c:4253 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline] __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline] netlink_deliver_tap+0x9b5/0xbc0 net/netlink/af_netlink.c:334 netlink_deliver_tap_kernel net/netlink/af_netlink.c:343 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x5e5/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 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:00007f0ee4eeb188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffcbc36da2f R14: 00007f0ee4eeb300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 19723 Comm: syz-executor.3 Not tainted 5.14.0-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:105 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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:342 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline] check_cpu_stall kernel/rcu/tree_stall.h:700 [inline] rcu_pending kernel/rcu/tree.c:3922 [inline] rcu_sched_clock_irq.cold+0x9f/0x747 kernel/rcu/tree.c:2641 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:1537 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:197 Code: 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 34 15 00 00 85 c0 74 2b 8b 82 10 15 00 00 <83> f8 02 75 20 48 8b 8a 18 15 00 00 8b 92 14 15 00 00 48 8b 01 48 RSP: 0018:ffffc90001aa75f0 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff88808cc702c0 RCX: 0000000000000000 RDX: ffff88802a764080 RSI: ffffffff874a42be RDI: 0000000000000003 RBP: dffffc0000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: ffffffff874a42da R11: 0000000000000000 R12: 0000000000000120 R13: 0000000000000900 R14: ffff88808c800000 R15: ffff88808cc70000 cake_drop net/sched/sch_cake.c:1515 [inline] cake_enqueue+0x139e/0x3a00 net/sched/sch_cake.c:1903 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3854 __dev_xmit_skb net/core/dev.c:3938 [inline] __dev_queue_xmit+0x1e28/0x3620 net/core/dev.c:4253 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline] __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline] netlink_deliver_tap+0x9b5/0xbc0 net/netlink/af_netlink.c:334 netlink_deliver_tap_kernel net/netlink/af_netlink.c:343 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x5e5/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 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:00007f0ee4f2d188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcbc36da2f R14: 00007f0ee4f2d300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 10 c3 adc %al,%bl 2: c3 retq 3: 89 74 24 0c mov %esi,0xc(%rsp) 7: 48 89 3c 24 mov %rdi,(%rsp) b: e8 4b dd 47 00 callq 0x47dd5b 10: 8b 74 24 0c mov 0xc(%rsp),%esi 14: 48 8b 3c 24 mov (%rsp),%rdi 18: eb 82 jmp 0xffffff9c 1a: e8 5c e2 47 00 callq 0x47e27b 1f: eb 07 jmp 0x28 21: 0f 00 2d c3 c5 55 08 verw 0x855c5c3(%rip) # 0x855c5eb 28: fb sti 29: f4 hlt * 2a: eb 9b jmp 0xffffffc7 <-- trapping instruction 2c: eb 07 jmp 0x35 2e: 0f 00 2d b6 c5 55 08 verw 0x855c5b6(%rip) # 0x855c5eb 35: f4 hlt 36: eb c5 jmp 0xfffffffd 38: 89 74 24 0c mov %esi,0xc(%rsp) 3c: 48 89 3c 24 mov %rdi,(%rsp)