rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=caa4/1/0x4000000000000000 softirq=15400/15408 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=10777, q=38 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6031 Comm: syz-executor.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:rb_red_parent lib/rbtree.c:66 [inline]
RIP: 0010:__rb_insert lib/rbtree.c:88 [inline]
RIP: 0010:rb_insert_color+0x26/0x810 lib/rbtree.c:436
Code: 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 57 48 89 fa 41 56 48 c1 ea 03 41 55 41 54 49 89 fc 55 53 48 83 ec 08 <80> 3c 02 00 0f 85 af 05 00 00 49 be 00 00 00 00 00 fc ff df 49 8b
RSP: 0018:ffffc90000007dc8 EFLAGS: 00000092
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8b8c1838
RDX: 1ffff1100e438a60 RSI: ffff8880b8428610 RDI: ffff8880721c5300
RBP: ffff8880721c5300 R08: 0000000000000006 R09: ffff8880721c5300
R10: ffff8880721c5300 R11: 0000000000000001 R12: ffff8880721c5300
R13: ffff8880721c5300 R14: ffff8880b84285c0 R15: dffffc0000000000
FS:  00007fa43a98e6c0(0000) GS:ffff888124342000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa43998c028 CR3: 0000000020b2b000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rb_insert_color_cached include/linux/rbtree.h:142 [inline]
 rb_add_cached include/linux/rbtree.h:211 [inline]
 timerqueue_add+0x28c/0x330 lib/timerqueue.c:40
 __run_hrtimer kernel/time/hrtimer.c:1802 [inline]
 __hrtimer_run_queues+0x863/0xa70 kernel/time/hrtimer.c:1849
 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1911
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x490 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056
 </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+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 d6 db 51 f6 48 89 df e8 be 2b 52 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 65 4c 42 f6 65 8b 05 5e be 7a 08 85 c0 74 16 5b
RSP: 0018:ffffc90004277148 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff8880721c52a8 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffffffff8de7798c RDI: ffffffff8c1b0b20
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880721c52a8
R13: 0000000000000246 R14: 0000000000000002 R15: 189ee51aff778240
 spin_unlock_irqrestore include/linux/spinlock.h:407 [inline]
 taprio_change+0x2819/0x39a0 net/sched/sch_taprio.c:1985
 taprio_init+0x69b/0x920 net/sched/sch_taprio.c:2124
 qdisc_create+0x47b/0x1090 net/sched/sch_api.c:1319
 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline]
 tc_modify_qdisc+0xdcf/0x2120 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6967
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa4398698a9
Code: 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa43a98e078 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa43998bf60 RCX: 00007fa4398698a9
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 00007fa4398deeec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa43998bf60 R15: 00007fff8c393438
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g10777 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:29256 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x583/0x1500 kernel/smp.c:877
Code: 00 fc ff df 48 8b 54 24 10 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 e4 63 0c 00 f3 90 41 0f b6 45 00 <41> 38 c4 7c 08 84 c0 0f 85 91 0d 00 00 8b 45 08 31 ff 83 e0 01 41
RSP: 0018:ffffc90000117878 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fc6c42
RDX: ffff88801e2c4980 RSI: ffffffff81fc6c1c RDI: ffff88801e2c4980
RBP: ffff8880b8442ee0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170885dd R14: 0000000000000001 R15: ffff8880b853c3c0
FS:  0000000000000000(0000) GS:ffff888124442000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4398ab390 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 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+0x337/0xc60 arch/x86/kernel/alternative.c:2971
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x37a/0x550 kernel/jump_label.c:919
 static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:900 [inline]
 toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:892
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>