rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (2 ticks this GP) idle=024c/1/0x4000000000000002 softirq=30827/30827 fqs=0
	(detected by 0, t=10503 jiffies, g=48713, q=390 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9161 Comm: syz.2.1315 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:ct_nmi_enter+0x5f/0x170 kernel/context_tracking.c:-1
Code: 33 d3 75 48 85 c0 0f 88 e0 00 00 00 e8 4a 08 00 00 89 c3 83 f8 08 0f 83 eb 00 00 00 48 8b 04 dd 80 f9 65 8c 8b 88 08 58 03 00 <65> 8b 05 92 4a d2 75 f7 c1 04 00 00 00 75 30 bf 04 00 00 00 e8 f8
RSP: 0018:ffffc900001e0500 EFLAGS: 00000097
RAX: ffff8880b8f00000 RBX: 0000000000000001 RCX: 000000000005024c
RDX: 0000000000000100 RSI: ffffffff8adf5dc0 RDI: ffffffff8adf5d80
RBP: ffffc900001e05c8 R08: ffffffff8e210aef R09: 1ffffffff1c4215d
R10: dffffc0000000000 R11: fffffbfff1c4215e R12: dffffc0000000000
R13: 0000000000000001 R14: ffff8880b8f35800 R15: 0000000000000000
FS:  00007f5e2e2d16c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5e2d2738e0 CR3: 00000000277ac000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000200 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 ct_irq_enter_irqson+0xaf/0x170 kernel/context_tracking.c:407
 trace_irq_enable_rcuidle+0x9f/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 a2 7c 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e06c0 EFLAGS: 00000206
RAX: 658f4cd07df49900 RBX: 1ffff9200003c0e0 RCX: 658f4cd07df49900
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffffc900001e07c0 R08: ffffffff90b10357 R09: 1ffffffff216206a
R10: dffffc0000000000 R11: fffffbfff216206b R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ndisc_send_skb+0xdc2/0x1520 net/ipv6/ndisc.c:521
 ndisc_send_ns net/ipv6/ndisc.c:671 [inline]
 ndisc_solicit+0x36b/0x660 net/ipv6/ndisc.c:763
 neigh_probe net/core/neighbour.c:1080 [inline]
 neigh_timer_handler+0xaba/0x1090 net/core/neighbour.c:1162
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 df 9e 0c 48 89 de 5b e9 77 62 50 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 14 41 80 7e 65 8b 15 15 41 80 7e 81 e2 00
RSP: 0018:ffffc9000d65fb08 EFLAGS: 00000246
RAX: 1ffff92001a8ff8c RBX: ffffc9000d47fc58 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffc90000a11cc8 RDI: ffffc9000d47fc58
RBP: ffffc9000d47fc58 R08: ffff88802d0bda2b R09: 1ffff11005a17b45
R10: dffffc0000000000 R11: ffffed1005a17b46 R12: ffffc9000d47fc80
R13: dffffc0000000000 R14: ffffc9000d47fc58 R15: ffffc9000d47fc60
 plist_check_prev_next lib/plist.c:35 [inline]
 plist_check_list+0xe3/0x240 lib/plist.c:48
 plist_check_head lib/plist.c:59 [inline]
 plist_del+0x56/0x3b0 lib/plist.c:114
 __futex_unqueue+0xe7/0x150 kernel/futex/core.c:518
 futex_wake_mark+0xe8/0x150 kernel/futex/waitwake.c:123
 futex_wake+0x32b/0x4f0 kernel/futex/waitwake.c:177
 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139
 __do_sys_futex kernel/futex/syscalls.c:211 [inline]
 __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5e2d39e019
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:00007f5e2e2d10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f5e2d625fa8 RCX: 00007f5e2d39e019
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f5e2d625fac
RBP: 00007f5e2d625fa0 R08: 0012cd511778f75e R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e2d626038 R14: 00007ffe490b1630 R15: 00007ffe490b1718
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g48713 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=25854
rcu: rcu_preempt kthread starved for 10503 jiffies! g48713 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:27600 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 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: 9161 Comm: syz.2.1315 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline]
RIP: 0010:__irq_work_queue_local+0x37/0x190 kernel/irq_work.c:85
Code: 00 00 00 00 00 fc ff df e8 d6 b0 f3 ff 4c 8d 73 08 4c 89 f7 be 04 00 00 00 e8 15 df 44 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 f6 00 00 00 45 8b 26 44 89 e6 83 e6 04 31 ff e8 01 b4
RSP: 0018:ffffc900001dfdf8 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff8880b8f3bbf0 RCX: ffffffff818e7d5b
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b8f3bbf8
RBP: 0000000000000001 R08: ffff8880b8f3bbfb R09: 1ffff110171e777f
R10: dffffc0000000000 R11: ffffed10171e7780 R12: 0000000000000000
R13: dffffc0000000001 R14: ffff8880b8f3bbf8 R15: dffffc0000000000
FS:  00007f5e2e2d16c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5e2d2738e0 CR3: 00000000277ac000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000200 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 irq_work_queue_on+0x13c/0x260 kernel/irq_work.c:165
 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 __perf_event_output kernel/events/core.c:7741 [inline]
 perf_event_output_forward+0x271/0x2f0 kernel/events/core.c:7750
 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9496
 perf_swevent_overflow kernel/events/core.c:9579 [inline]
 perf_swevent_event+0x315/0x570 kernel/events/core.c:9630
 perf_tp_event+0x36b/0xc10 kernel/events/core.c:10064
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 a2 7c 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e06c0 EFLAGS: 00000206
RAX: 658f4cd07df49900 RBX: 1ffff9200003c0e0 RCX: 658f4cd07df49900
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffffc900001e07c0 R08: ffffffff90b10357 R09: 1ffffffff216206a
R10: dffffc0000000000 R11: fffffbfff216206b R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ndisc_send_skb+0xdc2/0x1520 net/ipv6/ndisc.c:521
 ndisc_send_ns net/ipv6/ndisc.c:671 [inline]
 ndisc_solicit+0x36b/0x660 net/ipv6/ndisc.c:763
 neigh_probe net/core/neighbour.c:1080 [inline]
 neigh_timer_handler+0xaba/0x1090 net/core/neighbour.c:1162
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 df 9e 0c 48 89 de 5b e9 77 62 50 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 14 41 80 7e 65 8b 15 15 41 80 7e 81 e2 00
RSP: 0018:ffffc9000d65fb08 EFLAGS: 00000246
RAX: 1ffff92001a8ff8c RBX: ffffc9000d47fc58 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffc90000a11cc8 RDI: ffffc9000d47fc58
RBP: ffffc9000d47fc58 R08: ffff88802d0bda2b R09: 1ffff11005a17b45
R10: dffffc0000000000 R11: ffffed1005a17b46 R12: ffffc9000d47fc80
R13: dffffc0000000000 R14: ffffc9000d47fc58 R15: ffffc9000d47fc60
 plist_check_prev_next lib/plist.c:35 [inline]
 plist_check_list+0xe3/0x240 lib/plist.c:48
 plist_check_head lib/plist.c:59 [inline]
 plist_del+0x56/0x3b0 lib/plist.c:114
 __futex_unqueue+0xe7/0x150 kernel/futex/core.c:518
 futex_wake_mark+0xe8/0x150 kernel/futex/waitwake.c:123
 futex_wake+0x32b/0x4f0 kernel/futex/waitwake.c:177
 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139
 __do_sys_futex kernel/futex/syscalls.c:211 [inline]
 __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5e2d39e019
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:00007f5e2e2d10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f5e2d625fa8 RCX: 00007f5e2d39e019
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f5e2d625fac
RBP: 00007f5e2d625fa0 R08: 0012cd511778f75e R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e2d626038 R14: 00007ffe490b1630 R15: 00007ffe490b1718
 </TASK>