rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=d844/1/0x4000000000000000 softirq=21768/21771 fqs=1
rcu: 	(detected by 0, t=10503 jiffies, g=16697, q=487 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 753 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:751
Code: e8 bb ce b2 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 fd 9a 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 dc 1a 80 00 48 c7 c3 d8 46 81 92 49 03 1e 48 89
RSP: 0018:ffffc90000a08ce8 EFLAGS: 00000046
RAX: 1ffffffff1b35fbb RBX: 0000000000000001 RCX: 0000000000010003
RDX: ffff888024780000 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: 0000000000000001 R08: ffffffff8f822377 R09: 1ffffffff1f0446e
R10: dffffc0000000000 R11: fffffbfff1f0446f R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff8d9afdd8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2d7f2df286 CR3: 00000000735b0000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 trace_hrtimer_start include/trace/events/timer.h:222 [inline]
 debug_activate kernel/time/hrtimer.c:478 [inline]
 enqueue_hrtimer+0x9d/0x380 kernel/time/hrtimer.c:1081
 __run_hrtimer kernel/time/hrtimer.c:1794 [inline]
 __hrtimer_run_queues+0x636/0xc30 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 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:instrument_atomic_read include/linux/instrumented.h:68 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline]
RIP: 0010:__mutex_owner kernel/locking/mutex.h:47 [inline]
RIP: 0010:mutex_spin_on_owner+0x27b/0x360 kernel/locking/mutex.c:363
Code: be 08 00 00 00 e8 45 a5 89 00 42 80 7c 35 00 00 74 08 4c 89 e7 e8 c5 a2 89 00 49 f7 04 24 01 00 00 00 0f 85 8c 00 00 00 f3 90 <4c> 89 e7 be 08 00 00 00 e8 18 a5 89 00 42 80 7c 35 00 00 0f 84 90
RSP: 0018:ffffc900035976e8 EFLAGS: 00000246
RAX: 1ffff110048f0000 RBX: ffffffff8f311e30 RCX: ffffffff819d7548
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: 1ffffffff1e623bc R08: ffffffff8f311de7 R09: 1ffffffff1e623bc
R10: dffffc0000000000 R11: fffffbfff1e623bd R12: ffffffff8f311de0
R13: ffffffff8f311e30 R14: dffffc0000000000 R15: ffff8880274d0000
 mutex_optimistic_spin kernel/locking/mutex.c:480 [inline]
 __mutex_lock_common kernel/locking/mutex.c:618 [inline]
 __mutex_lock+0x311/0x1350 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g16697 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27808 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 4553 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
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 54 0e da 0b 48 89 de 5b e9 b3 fb 5a 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 0c 25 08 10 80 92 65 8b 15 58 18 bf 10 81 e2 00 01 ff 00
RSP: 0018:ffffc9000ead7698 EFLAGS: 00000202
RAX: ffffffff81b5644d RBX: 1ffff110170e8129 RCX: ffff888033300000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ead77e0 R08: ffffffff8f822377 R09: 1ffffffff1f0446e
R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdba91f1000 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xcdd/0x1260 kernel/smp.c:877
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
 smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
 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+0xad/0x240 mm/kfence/core.c:874
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>