rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=9364/1/0x4000000000000000 softirq=27824/27824 fqs=214
rcu: 	(t=10502 jiffies g=31409 q=888 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10074 jiffies! g31409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=9341
rcu: rcu_preempt kthread starved for 10077 jiffies! g31409 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:27736 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5647 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: fc 7e 02 e9 13 05 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 ae 18 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000a08468 EFLAGS: 00000246
RAX: ffffffff8176b19a RBX: 0000000000000003 RCX: ffff888012139f00
RDX: 0000000000000100 RSI: ffffffff8e22c582 RDI: ffffffff8c4bdc80
RBP: 0000000000000003 R08: ffffffff90578d37 R09: 1ffffffff20af1a6
R10: dffffc0000000000 R11: fffffbfff20af1a7 R12: 0000000000000200
R13: 0000000000000000 R14: ffff888033a9e158 R15: dffffc0000000000
FS:  000055558598c500(0000) GS:ffff888125050000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555736ab4e8 CR3: 000000005c9d6000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 kvm_wait+0x10f/0x150 arch/x86/kernel/kvm.c:1096
 pv_wait arch/x86/include/asm/paravirt-spinlock.h:83 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
 __pv_queued_spin_lock_slowpath+0x74a/0xbc0 kernel/locking/qspinlock.c:325
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x26c/0x2f0 kernel/locking/spinlock_debug.c:116
 spin_lock include/linux/spinlock.h:342 [inline]
 __dev_xmit_skb net/core/dev.c:4252 [inline]
 __dev_queue_xmit+0xd56/0x3820 net/core/dev.c:4836
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x337/0x540 net/ipv6/ip6_output.c:246
 dst_output include/net/dst.h:471 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ndisc_send_skb+0xcb2/0x1650 net/ipv6/ndisc.c:512
 addrconf_rs_timer+0x2d2/0x6c0 net/ipv6/addrconf.c:4072
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x417/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 63 ea 3d 0a e8 8e a9 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900044af980 EFLAGS: 00000206
RAX: 0000000000087295 RBX: ffff8880b873bf20 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8e22c582 RDI: ffffffff8c4bdc80
RBP: ffffc900044af9d0 R08: ffffffff90578d37 R09: 1ffffffff20af1a6
R10: dffffc0000000000 R11: fffffbfff20af1a7 R12: ffff888012139f00
R13: ffff8880b873bee8 R14: dffffc0000000000 R15: 1ffff110170e77e4
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x17e1/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 do_nanosleep+0x21e/0x6a0 kernel/time/hrtimer.c:2399
 hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2445
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1406 [inline]
 __se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1383
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe545d5e6ce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fe54614fd28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055558598c500 RCX: 00007fe545d5e6ce
RDX: 00007fe54614fd80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe54614fdec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388
R13: 00000000000927c0 R14: 000000000002a0e2 R15: 00007fe54614fe40
 </TASK>
CPU: 0 UID: 0 PID: 7029 Comm: syz.4.301 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x70 kernel/kcov.c:222
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 24 17 00 00 00 74 2c 8b 91 f8 16 00 00 83 fa 02 75 21 48 8b 91 00 17 00 00 48 8b 32 <48> 8d 7e 01 8b 89 fc 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2
RSP: 0018:ffffc90003aff198 EFLAGS: 00000246
RAX: ffffffff89dfbec7 RBX: ffff88807eaff470 RCX: ffff888032ca9f00
RDX: ffffc9001bb76000 RSI: 000000000007ffff RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888033a9e290 R09: 00000000fff10000
R10: ffff888033a9e290 R11: 00000000fff10000 R12: ffff88807eaff460
R13: ffff88807eaff40c R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f4ec25f46c0(0000) GS:ffff888124f50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000e000 CR3: 0000000031cf8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 basic_classify+0x257/0x2d0 net/sched/cls_basic.c:55
 tc_classify include/net/tc_wrapper.h:198 [inline]
 __tcf_classify net/sched/cls_api.c:1764 [inline]
 tcf_classify+0x43d/0x1160 net/sched/cls_api.c:1860
 tcf_classify_qdisc include/net/pkt_cls.h:164 [inline]
 hfsc_classify net/sched/sch_hfsc.c:1146 [inline]
 hfsc_enqueue+0x322/0xf80 net/sched/sch_hfsc.c:1545
 dev_qdisc_enqueue+0x4e/0x260 net/core/dev.c:4179
 __dev_xmit_skb net/core/dev.c:4294 [inline]
 __dev_queue_xmit+0x1b45/0x3820 net/core/dev.c:4836
 packet_snd net/packet/af_packet.c:3082 [inline]
 packet_sendmsg+0x3d95/0x5040 net/packet/af_packet.c:3114
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ec179de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4ec25f4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4ec1a25fa0 RCX: 00007f4ec179de99
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000007
RBP: 00007f4ec1833eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ec1a26038 R14: 00007f4ec1a25fa0 R15: 00007f4ec1b4fa48
 </TASK>
sched: DL replenish lagged too much