rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=2a24/1/0x4000000000000000 softirq=130577/130577 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19561/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=141229, q=779 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 19560 Comm: syz.3.2647 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:453 [inline]
RIP: 0010:__lock_acquire+0x576/0x2630 kernel/locking/lockdep.c:5225
Code: c1 c7 08 31 d7 89 fa 29 f8 01 f7 c1 c2 10 41 89 f8 31 c2 89 d0 29 d6 01 fa c1 c8 0d 31 c6 89 f0 41 29 f0 01 f2 c1 c0 04 89 d2 <44> 31 c0 48 c1 e0 20 48 09 d0 49 89 c7 4d 85 e4 74 46 8b 85 88 0b
RSP: 0018:ffffc90000a08c80 EFLAGS: 00000806
RAX: 000000004baaed78 RBX: ffff888063528be0 RCX: 0000000000000002
RDX: 0000000062f81a6f RSI: 0000000084baaed7 RDI: 00000000fc9e783c
RBP: ffff888063528000 R08: 0000000077e3c965 R09: 0000000000000d3f
R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000d3f R14: 0000000000000000 R15: 0000000000000003
FS: 00007fa618e846c0(0000) GS:ffff888124472000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000012c0 CR3: 0000000029a70000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
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:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 06 1a 57 f6 48 89 df e8 de 69 57 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 65 39 47 f6 65 8b 05 1e 7f 7d 08 85 c0 74 16 5b
RSP: 0018:ffffc90003fc7168 EFLAGS: 00000246
RAX: 0000000000000012 RBX: ffff8880485dc2a8 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffffffff8df211b7 RDI: ffffffff8c1c3800
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880485dc2a8
R13: 0000000000000246 R14: 0000000000000001 R15: 18af69ea93dd4ad0
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
taprio_change+0x2819/0x39a0 net/sched/sch_taprio.c:1986
taprio_init+0x69b/0x920 net/sched/sch_taprio.c:2125
qdisc_create+0x47b/0x1070 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:7005
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
__sys_sendmsg+0x170/0x220 net/socket.c:2784
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa617f9ce59
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:00007fa618e84028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa618215fa0 RCX: 00007fa617f9ce59
RDX: 0000000000000010 RSI: 00002000000012c0 RDI: 0000000000000006
RBP: 00007fa618032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa618216038 R14: 00007fa618215fa0 R15: 00007ffcc64b6ca8
task:dhcpcd-run-hook state:R running task stack:27320 pid:19561 tgid:19561 ppid:19549 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find+0x49/0xf0 arch/x86/kernel/unwind_orc.c:101
Code: 00 49 89 fe 48 89 f0 49 39 fc 72 7b 48 b9 00 00 00 00 00 fc ff df 49 89 ff 48 89 fd eb 0c 48 8d 6b 04 49 89 df 49 39 ec 72 4e <4c> 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1
RSP: 0018:ffffc900043ef370 EFLAGS: 00000206
RAX: ffffffff916cf0f2 RBX: ffffffff90e978fc RCX: dffffc0000000000
RDX: ffffffff8100015e RSI: 0000000000000000 RDI: ffffffff90e978e0
RBP: ffffffff90e978e0 R08: ffffffff916cf1be R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000001 R12: ffffffff90e978f8
R13: ffffffff8100012f R14: ffffffff90e978e0 R15: ffffffff90e978e0
orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
unwind_next_frame+0x2ec/0x2090 arch/x86/kernel/unwind_orc.c:510
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
folios_put_refs+0x571/0xa90 mm/swap.c:1008
free_pages_and_swap_cache+0x22d/0x3b0 mm/swap_state.c:401
__tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:138
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
tlb_flush_mmu mm/mmu_gather.c:424 [inline]
tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa10 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1178
mmput+0x67/0x80 kernel/fork.c:1201
exit_mm kernel/exit.c:581 [inline]
do_exit+0x833/0x2a60 kernel/exit.c:963
do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
__do_sys_exit_group kernel/exit.c:1129 [inline]
__se_sys_exit_group kernel/exit.c:1127 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1127
x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4aea21d6c5
RSP: 002b:00007ffd180a5c28 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffd180a5f04 RCX: 00007f4aea21d6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffd180a5d20 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffd180a5f60 R14: 00007f4aea42d000 R15: 000055b10ba79d98
rcu: rcu_preempt kthread starved for 10497 jiffies! g141229 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:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
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+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1327 Comm: kworker/u8:8 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x5a3/0x1700 kernel/smp.c:892
Code: e4 07 49 01 c5 41 83 c4 03 e8 79 83 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31 ff 83 e0 01 <41> 89 c6 89 c6 e8 03 7e 0c 00 45 85 f6 75 d0 e8 49 83 0c 00 e8 44
RSP: 0018:ffffc900060d7870 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81fc138d
RDX: ffff88802bb5a500 RSI: ffffffff81fc1367 RDI: 0000000000000000
RBP: ffff8880b8540f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81e9 R14: 0000000000000001 R15: ffff8880b843c5c0
FS: 0000000000000000(0000) GS:ffff888124372000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4aea31f7d0 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 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+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
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:906 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245