rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=b93c/1/0x4000000000000000 softirq=170949/170950 fqs=1
rcu: 	(detected by 1, t=10506 jiffies, g=191549, q=618 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4173 Comm: syz.3.8729 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:mark_usage kernel/locking/lockdep.c:4620 [inline]
RIP: 0010:__lock_acquire+0x5f2/0x2cf0 kernel/locking/lockdep.c:5191
Code: 00 0f 8c 0b ff ff ff 44 89 e0 38 04 24 76 16 e8 44 e3 0a 03 85 c0 74 0d 83 3d 4d c9 90 0e 00 0f 84 0a 08 00 00 83 7c 24 10 00 <0f> 84 a8 00 00 00 41 8b 45 20 66 85 c0 0f 88 8c 00 00 00 65 8b 0d
RSP: 0018:ffffc90000007b40 EFLAGS: 00000002
RAX: 0000000000000002 RBX: ffff88809c0f49a8 RCX: 0000000000000003
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff88809c0f4988 R08: ffffffff84b9ba73 R09: ffffffff9a686690
R10: dffffc0000000000 R11: fffff52000000fac R12: 0000000000000002
R13: ffff88809c0f4988 R14: ffff88809c0f3d80 R15: 0000000000000003
FS:  00007f8b7a6b76c0(0000) GS:ffff888125245000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556c0574e8 CR3: 00000000a9f78000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
 debug_object_activate+0x83/0x580 lib/debugobjects.c:835
 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
 debug_activate kernel/time/hrtimer.c:528 [inline]
 enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109
 __run_hrtimer kernel/time/hrtimer.c:1946 [inline]
 __hrtimer_run_queues+0x4d2/0xa20 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 0d 5c ec f5 f7 c3 00 02 00 00 74 05 e8 10 78 17 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> a4 ed dd f5 65 8b 05 9d f0 87 07 85 c0 74 18 5b 41 5e e9 41 48
RSP: 0018:ffffc90004756ee8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000282 RCX: 0000000080000202
RDX: 0000000000000002 RSI: ffffffff8dfb65fa RDI: 0000000000000001
RBP: ffffc900047571d0 R08: ffffffff903215b7 R09: 1ffffffff20642b6
R10: dffffc0000000000 R11: fffffbfff20642b7 R12: ffff8880623de290
R13: dffffc0000000000 R14: ffff8880623de2a8 R15: ffff8880623de2f8
 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
 taprio_change+0x30fe/0x3e50 net/sched/sch_taprio.c:1985
 taprio_init+0x96f/0xbe0 net/sched/sch_taprio.c:2124
 qdisc_create+0x7c4/0xf20 net/sched/sch_api.c:1319
 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline]
 tc_modify_qdisc+0x16f0/0x2290 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:7003
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
 __sys_sendmsg net/socket.c:2784 [inline]
 __do_sys_sendmsg net/socket.c:2789 [inline]
 __se_sys_sendmsg net/socket.c:2787 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b7979c819
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:00007f8b7a6b7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8b79a16090 RCX: 00007f8b7979c819
RDX: 0000000000000010 RSI: 00002000000012c0 RDI: 0000000000000006
RBP: 00007f8b79832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b79a16128 R14: 00007f8b79a16090 R15: 00007ffe07952ff8
 </TASK>
rcu: rcu_preempt kthread starved for 10499 jiffies! g191549 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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7183
 __schedule_loop kernel/sched/core.c:7262 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7277
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 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: 48 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe32/0x1210 kernel/smp.c:892
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 77 e7 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 22 e3 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 06 e3
RSP: 0018:ffffc90000b87700 EFLAGS: 00000293
RAX: ffffffff81b97aea RBX: 1ffff110170c8541 RCX: ffff88801b72dc40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b87840 R08: ffffffff903215b7 R09: 1ffffffff20642b6
R10: dffffc0000000000 R11: fffffbfff20642b7 R12: ffff8880b8642a08
R13: dffffc0000000000 R14: ffff8880b873c148 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125345000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b555eb4b8 CR3: 000000000e74a000 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:2761 [inline]
 smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2971
 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:900
 process_one_work kernel/workqueue.c:3288 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452
 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>