rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=647c/1/0x4000000000000000 softirq=16300/16301 fqs=12
	(t=10502 jiffies g=15929 q=379 ncpus=2)
rcu: rcu_preempt kthread starved for 10478 jiffies! g15929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28096 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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 PID: 5534 Comm: syz.4.115 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:perf_callchain_store include/linux/perf_event.h:1390 [inline]
RIP: 0010:perf_callchain_kernel+0x3c9/0x5c0 arch/x86/events/core.c:2807
Code: 8b 3a 44 89 e7 44 89 fe e8 a4 d7 7f 00 45 39 fc 0f 83 58 01 00 00 49 bf 00 00 00 00 00 fc ff df 48 8b 44 24 30 42 0f b6 04 38 <84> c0 0f 85 e9 00 00 00 48 8b 44 24 08 80 38 01 4c 8b 64 24 20 0f
RSP: 0018:ffffc900001deea0 EFLAGS: 00000097
RAX: 0000000000000000 RBX: 1ffff9200003bddc RCX: 0000000000000100
RDX: ffff888025805940 RSI: 000000000000007f RDI: 0000000000000024
RBP: ffffc900001defd0 R08: dffffc0000000000 R09: ffffc900001def50
R10: fffff5200003bdec R11: 1ffff9200003bdea R12: 0000000000000024
R13: ffffffff8a1ff227 R14: 1ffff9200003be05 R15: dffffc0000000000
FS:  00007fa51934e6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 00000000718f3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 get_perf_callchain+0x376/0x480 kernel/events/callchain.c:200
 perf_callchain kernel/events/core.c:7512 [inline]
 perf_prepare_sample+0x399/0x2040 kernel/events/core.c:7545
 __perf_event_output kernel/events/core.c:7730 [inline]
 perf_event_output_forward+0x163/0x2a0 kernel/events/core.c:7750
 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
 perf_tp_event+0x335/0xb60 kernel/events/core.c:10029
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10002
 perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14
 trace_irq_disable include/trace/events/preemptirq.h:36 [inline]
 trace_hardirqs_off_finish+0x13f/0x180 kernel/trace/trace_preemptirq.c:67
 irqentry_enter+0x33/0x50 kernel/entry/common.c:382
 sysvec_irq_work+0xa/0xc0 arch/x86/kernel/irq_work.c:17
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:seqcount_lockdep_reader_access+0x17b/0x1c0 include/linux/seqlock.h:105
Code: 00 4d 85 e4 75 16 e8 04 8f 0f 00 eb 15 e8 fd 8e 0f 00 e8 88 11 a6 08 4d 85 e4 74 ea e8 ee 8e 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc900001df800 EFLAGS: 00000246
RAX: ffffffff81714132 RBX: 0000000000000000 RCX: ffff888025805940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001df8b8 R08: dffffc0000000000 R09: fffffbfff215c46a
R10: fffffbfff215c46a R11: 1ffffffff215c469 R12: 0000000000000200
R13: 000001fb6d394f62 R14: 1ffff9200003bf00 R15: dffffc0000000000
 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
 ktime_get_with_offset+0xff/0x320 kernel/time/timekeeping.c:891
 ktime_get_real include/linux/timekeeping.h:79 [inline]
 netif_rx_internal+0x398/0x560 net/core/dev.c:5023
 __netif_rx+0x74/0xb0 net/core/dev.c:5066
 veth_forward_skb drivers/net/veth.c:290 [inline]
 veth_xmit+0x650/0xb00 drivers/net/veth.c:343
 __netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 netdev_start_xmit include/linux/netdevice.h:4910 [inline]
 xmit_one net/core/dev.c:3670 [inline]
 dev_hard_start_xmit+0x262/0x870 net/core/dev.c:3686
 __dev_queue_xmit+0x1bf1/0x3760 net/core/dev.c:4346
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 br_dev_queue_push_xmit+0x6a2/0x850 net/bridge/br_forward.c:53
 NF_HOOK+0x33c/0x3d0 include/linux/netfilter.h:302
 br_forward_finish+0xcf/0x120 net/bridge/br_forward.c:66
 NF_HOOK+0x33c/0x3d0 include/linux/netfilter.h:302
 __br_forward+0x41f/0x600 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0xb5/0x150 net/bridge/br_forward.c:189
 br_flood+0x2fc/0x450 net/bridge/br_forward.c:231
 br_dev_xmit+0x104a/0x16e0 net/bridge/br_device.c:105
 __netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 netdev_start_xmit include/linux/netdevice.h:4910 [inline]
 xmit_one net/core/dev.c:3670 [inline]
 dev_hard_start_xmit+0x262/0x870 net/core/dev.c:3686
 __dev_queue_xmit+0x1bf1/0x3760 net/core/dev.c:4346
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 neigh_hh_output include/net/neighbour.h:529 [inline]
 neigh_output include/net/neighbour.h:543 [inline]
 ip6_finish_output2+0xd6b/0x1590 net/ipv6/ip6_output.c:138
 dst_output include/net/dst.h:453 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xbfb/0x1510 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3979
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 10 f0 c8 08 e8 db b2 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900046378d8 EFLAGS: 00000286
RAX: 4196b281e1e86a00 RBX: 0000000000000000 RCX: 4196b281e1e86a00
RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: ffffffff8adefae0
RBP: ffffc90004637930 R08: dffffc0000000000 R09: ffffed10171e7551
R10: ffffed10171e7551 R11: 1ffff110171e7550 R12: ffff888025805940
R13: dffffc0000000000 R14: ffff88807ad23b80 R15: ffff8880b8f3b550
 context_switch kernel/sched/core.c:5247 [inline]
 __schedule+0x10f4/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 futex_wake+0x3fc/0x4b0 kernel/futex/waitwake.c:183
 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:111
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x14a/0x440 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa51858ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa51934e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fa5187b5fa8 RCX: 00007fa51858ebe9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fa5187b5fac
RBP: 00007fa5187b5fa0 R08: 003a75d60680e098 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa5187b6038 R14: 00007ffe379259e0 R15: 00007ffe37925ac8
 </TASK>
CPU: 0 PID: 5527 Comm: syz.0.111 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:379 [inline]
RIP: 0010:__rcu_read_lock+0x17/0x50 kernel/rcu/tree_plugin.h:402
Code: 8c 01 fb ff ff 4c 89 f7 e8 56 16 65 00 e9 f4 fa ff ff 90 53 65 48 8b 1d e7 98 96 7e 48 81 c3 3c 04 00 00 48 89 d8 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 11 ff 03 8b 03
RSP: 0018:ffffc90000007a00 EFLAGS: 00000a07
RAX: 1ffff110056cf087 RBX: ffff88802b67843c RCX: ffff88802b678000
RDX: 0000000000000100 RSI: 0000000000000004 RDI: ffff8880549ab850
RBP: 0000000000000038 R08: dffffc0000000000 R09: ffffed100f02469d
R10: ffffed100f02469d R11: 1ffff1100f02469c R12: dffffc0000000000
R13: 0000000000000038 R14: ffff88807af30000 R15: ffff8880549ab836
FS:  00007fb09476e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 0000000054913000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:789 [inline]
 ndisc_alloc_skb+0x185/0x450 net/ipv6/ndisc.c:436
 ndisc_send_rs+0x2a2/0x610 net/ipv6/ndisc.c:707
 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3979
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 0e c2 65 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c6 4b 36 f7 65 8b 05 e7 04 e1 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003fcfac0 EFLAGS: 00000206
RAX: 01f0448910137100 RBX: 0000000000000a02 RCX: 01f0448910137100
RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: 0000000000000001
RBP: ffffc90003fcfb48 R08: dffffc0000000000 R09: ffffed1005bfe141
R10: ffffed1005bfe141 R11: 1ffff11005bfe140 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88802dff0a00 R15: 1ffff920007f9f58
 try_to_wake_up+0x64c/0x1080 kernel/sched/core.c:4229
 wake_up_process kernel/sched/core.c:4361 [inline]
 wake_up_q+0x78/0xc0 kernel/sched/core.c:1009
 futex_wake+0x409/0x4b0 kernel/futex/waitwake.c:184
 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:111
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x14a/0x440 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb09398ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb09476e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fb093bb5fa8 RCX: 00007fb09398ebe9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fb093bb5fac
RBP: 00007fb093bb5fa0 R08: 002b8f2387ae0270 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb093bb6038 R14: 00007ffc25a0a120 R15: 00007ffc25a0a208
 </TASK>