rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=8f4c/1/0x4000000000000000 softirq=17757/17788 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6146/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=10485, q=3899 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6165 Comm: rm Not tainted 6.16.0-rc2-next-20250618-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_is_held_type+0x118/0x190 kernel/locking/lockdep.c:5945
Code: 01 00 00 00 48 c7 c7 f9 aa b7 8d e8 62 16 00 00 b8 ff ff ff ff 65 0f c1 05 35 83 34 07 83 f8 01 75 44 48 c7 04 24 00 00 00 00 <9c> 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01
RSP: 0018:ffffc90000007c28 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000001 RCX: d6a3f6d43b02f100
RDX: ffff888025c9da00 RSI: ffffffff8db7aaf9 RDI: ffffffff8be2f5e0
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f7c R12: 0000000000000046
R13: ffff888025c9da00 R14: ffff8880349a0300 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888125c3d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7337546e9c CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0xe7/0xc90 net/sched/sch_taprio.c:925
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb fa ff 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900055ff0b8 EFLAGS: 00000206
RAX: d6a3f6d43b02f100 RBX: 0000000000000000 RCX: d6a3f6d43b02f100
RDX: 0000000000000000 RSI: ffffffff8db7aaf9 RDI: ffffffff8be2f5e0
RBP: ffffffff81729c65 R08: 0000000000000000 R09: ffffffff81729c65
R10: ffffc900055ff288 R11: fffff52000abfe5d R12: 0000000000000002
R13: ffffffff8e13ee60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
folios_put_refs+0x559/0x640 mm/swap.c:992
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x44c/0xb50 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1120
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
__do_sys_exit_group kernel/exit.c:1111 [inline]
__se_sys_exit_group kernel/exit.c:1109 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f73376a56c5
Code: Unable to access opcode bytes at 0x7f73376a569b.
RSP: 002b:00007ffdb7a26338 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f73377a6fe8 RCX: 00007f73376a56c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007ffdb7a262c8 R09: 0000000000000000
R10: 00007ffdb7a26160 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f73377a5680 R15: 00007f73377a7000
task:syz.3.49 state:R running task stack:26952 pid:6146 tgid:6146 ppid:5842 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6876
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6900
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
wp_page_copy mm/memory.c:3688 [inline]
do_wp_page+0x1d1d/0x5800 mm/memory.c:4048
handle_pte_fault mm/memory.c:6103 [inline]
__handle_mm_fault+0x1144/0x5620 mm/memory.c:6230
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6399
do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f999c061865
RSP: 002b:00007ffc5cd397d0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 00000000000193c1 RCX: 00007f999c3b20c0
RDX: 00007f999c3b20c0 RSI: 0000000000000080 RDI: 00007f999c3b5fa0
RBP: 0000000000000bea R08: 00007f999c3b5fa0 R09: 000000015cd39b0f
R10: 00007ffc5cd39910 R11: 0000000000000246 R12: 00007f999c3b5fa0
R13: 00007f999c3b5fa0 R14: 0000000000019fab R15: 00007ffc5cd39930
rcu: rcu_preempt kthread starved for 10500 jiffies! g10485 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2060
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2262
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.16.0-rc2-next-20250618-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 a0 69 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4b 65 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 30 65 0b
RSP: 0018:ffffc900001276a0 EFLAGS: 00000293
RAX: ffffffff81b4f210 RBX: ffff8880b873b180 RCX: ffff88801cea8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000127800 R08: ffffffff8fa16cf7 R09: 1ffffffff1f42d9e
R10: dffffc0000000000 R11: fffffbfff1f42d9f R12: 1ffff110170c832d
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641968
FS: 0000000000000000(0000) GS:ffff888125d3d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c343c14 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245