rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=b0e/1/0x4000000000000000 softirq=290602/290603 fqs=17 (t=10502 jiffies g=449065 q=232) rcu: rcu_preempt kthread timer wakeup didn't happen for 10468 jiffies! g449065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=188883 rcu: rcu_preempt kthread starved for 10471 jiffies! g449065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:29232 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x934/0x2710 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline] rcu_gp_kthread+0xd1a/0x2300 kernel/rcu/tree.c:2177 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 25033 Comm: syz-executor.3 Tainted: G W 5.13.0-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 fb 7e 48 00 8b 74 24 0c 48 8b 3c 24 eb 82 e8 0c 84 48 00 eb 07 0f 00 2d f3 cf 55 08 fb f4 9b eb 07 0f 00 2d e6 cf 55 08 f4 eb c5 89 74 24 0c 48 89 3c 24 RSP: 0018:ffffc9000245f5e8 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1bd6759 RDX: 0000000000000000 RSI: ffffffff817b9a21 RDI: ffffffff813315c4 RBP: ffff8880a50580f0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817b9a08 R11: 0000000000000000 R12: 0000000000000000 R13: ffffed1014a0b01e R14: 0000000000000001 R15: ffff8880b9d36840 FS: 00007f490fb9d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc3620f4d7 CR3: 0000000092124000 CR4: 00000000001506e0 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:3901 [inline] __dev_queue_xmit+0x1d04/0x36a0 net/core/dev.c:4241 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline] __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline] netlink_deliver_tap+0x996/0xba0 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+0x85b/0xda0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:722 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2385 ___sys_sendmsg+0xf3/0x170 net/socket.c:2439 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2468 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: 0033:0x4665d9 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:00007f490fb9d188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffdd6d1d8ff R14: 00007f490fb9d300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 25024 Comm: syz-executor.3 Tainted: G W 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:96 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:341 print_cpu_stall kernel/rcu/tree_stall.h:624 [inline] check_cpu_stall kernel/rcu/tree_stall.h:699 [inline] rcu_pending kernel/rcu/tree.c:3911 [inline] rcu_sched_clock_irq.cold+0x9f/0x747 kernel/rcu/tree.c:2649 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 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+0x1c0/0xe40 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_cmp4+0x8/0x70 kernel/kcov.c:258 Code: 44 30 e0 02 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 <4c> 8b 14 24 89 f1 65 48 8b 34 25 00 f0 01 00 e8 64 ef ff ff 84 c0 RSP: 0018:ffffc900016af5d0 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000030 RCX: ffffc9000fb36000 RDX: 0000000000040000 RSI: 0000000000000017 RDI: 0000000000000003 RBP: 0000000000000017 R08: 0000000000000017 R09: 0000000000000000 R10: ffffffff87411a99 R11: 0000000000000000 R12: ffff8880a50582c0 R13: 0000000000000017 R14: 0000000000000000 R15: dffffc0000000000 cake_heapify+0x2e8/0x3d0 net/sched/sch_cake.c:1443 cake_drop net/sched/sch_cake.c:1515 [inline] cake_enqueue+0x13c9/0x39f0 net/sched/sch_cake.c:1903 __dev_xmit_skb net/core/dev.c:3926 [inline] __dev_queue_xmit+0x1e18/0x36a0 net/core/dev.c:4241 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline] __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline] netlink_deliver_tap+0x996/0xba0 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+0x85b/0xda0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:722 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2385 ___sys_sendmsg+0xf3/0x170 net/socket.c:2439 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2468 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: 0033:0x4665d9 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:00007f490fbdf188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffdd6d1d8ff R14: 00007f490fbdf300 R15: 0000000000022000