rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (3 ticks this GP) idle=727c/1/0x4000000000000000 softirq=55902/55903 fqs=2
rcu: 	(detected by 1, t=10505 jiffies, g=51917, q=673 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14948 Comm: syz.2.2595 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:base_update_next_timer kernel/time/hrtimer.c:1128 [inline]
RIP: 0010:__remove_hrtimer+0x201/0x3e0 kernel/time/hrtimer.c:1162
Code: eb 0f e8 f2 0a 13 00 48 bb ff ff ff ff ff ff ff 7f 49 83 c7 48 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 5f 60 7e 00 <49> 89 1f 80 7c 24 04 00 74 2d 48 8b 5c 24 08 4c 8d 7b 68 4c 89 f8
RSP: 0018:ffffc90000007d90 EFLAGS: 00000046
RAX: 1ffff110170c5069 RBX: 7fffffffffffffff RCX: ffff88803714be00
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000020
RBP: dffffc0000000000 R08: ffff8880520fd327 R09: 0000000000000000
R10: ffff8880520fd318 R11: ffffed100a41fa65 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880520fd300 R15: ffff8880b8628348
FS:  00007f8702a3c6c0(0000) GS:ffff88812527c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd4dcfa1ff8 CR3: 0000000037610000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:2012 [inline]
 __hrtimer_run_queues+0x295/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d 34 da 61 0c 48 89 de 5b e9 33 f8 5f 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d d8 49 74 11 65 8b 15 f9 49 74 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900081dfb38 EFLAGS: 00000246
RAX: ffffffff89bf11ef RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff89bf11bb RSI: ffffffff8fe43b20 RDI: 0000000000000000
RBP: ffffc900081dfcd0 R08: ffff88803714be00 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000002 R12: ffffc9000881c060
R13: 1ffff9200103bf80 R14: ffffc900081dfd60 R15: dffffc0000000000
 bpf_prog_test_run_sk_lookup+0x61f/0xbb0 net/bpf/test_run.c:1617
 bpf_prog_test_run+0x2c5/0x340 kernel/bpf/syscall.c:4742
 __sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6292
 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6385 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6385
 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: 0033:0x7f8701b9ce59
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:00007f8702a3c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f8701e15fa0 RCX: 00007f8701b9ce59
RDX: 0000000000000048 RSI: 0000200000000440 RDI: 000000000000000a
RBP: 00007f8701c32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8701e16038 R14: 00007f8701e15fa0 R15: 00007ffdb3ae7598
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g51917 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:28152 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7322
 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:
CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b0/0x14b0 kernel/smp.c:892
Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 98 02 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 44 fe 0b 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 29 fe 0b
RSP: 0018:ffffc90000ab7720 EFLAGS: 00000293
RAX: ffffffff81b9f7f7 RBX: dffffc0000000000 RCX: ffff888020698000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000ab7860 R08: ffffffff903117f7 R09: 1ffffffff20622fe
R10: dffffc0000000000 R11: fffffbfff20622ff R12: 1ffff110170c85c5
R13: ffff8880b873c2c8 R14: ffff8880b8642e28 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75bc17de9c CR3: 000000000e746000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
 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>