rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=970c/1/0x4000000000000000 softirq=93275/93275 fqs=1
rcu: (detected by 0, t=10502 jiffies, g=116369, q=509 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16803 Comm: syz.1.2816 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:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
RIP: 0010:lock_is_held_type+0xd7/0x140 kernel/locking/lockdep.c:5941
Code: 03 0f 95 c0 44 39 e0 0f 94 c0 0f b6 c0 48 c7 c7 06 cf ef 8d 89 44 24 04 e8 a6 17 00 00 ba ff ff ff ff 65 0f c1 15 f1 95 80 08 <83> fa 01 8b 44 24 04 75 2d 9c 5a 80 e6 02 75 47 41 f7 c5 00 02 00
RSP: 0018:ffffc90000a08d98 EFLAGS: 00000057
RAX: 0000000000000001 RBX: ffff88802c6652c0 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8defcf06 RDI: ffffffff8c1c3a00
RBP: ffff888026a3ca00 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 00000000ffffffff
R13: 0000000000000046 R14: ffff888026a3d630 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff88812446d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3340eff8 CR3: 0000000037356000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0x8c6/0xd20 net/sched/sch_taprio.c:931
__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:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 3b a2 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 46 41 f3 0e 0f 82 a4 02 00 00 8b 35 ce 74 f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd a1 26 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc90005177670 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000003
RDX: 0000000000000000 RSI: ffffffff8defcf06 RDI: ffffffff8c1c3a00
RBP: ffffffff8e7e57a0 R08: 00000000acf70bd3 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
page_table_check_clear+0x2ae/0x8f0 mm/page_table_check.c:77
__page_table_check_pte_clear+0xf1/0x100 mm/page_table_check.c:155
page_table_check_pte_clear include/linux/page_table_check.h:55 [inline]
ptep_get_and_clear_full arch/x86/include/asm/pgtable.h:1263 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:845 [inline]
zap_present_folio_ptes mm/memory.c:1632 [inline]
zap_present_ptes mm/memory.c:1714 [inline]
do_zap_pte_range mm/memory.c:1816 [inline]
zap_pte_range mm/memory.c:1918 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x2da3/0x4bf0 mm/memory.c:2093
unmap_vmas+0x299/0x5f0 mm/memory.c:2162
exit_mmap+0x1ef/0xa10 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1178
mmput+0x67/0x80 kernel/fork.c:1201
exit_mm kernel/exit.c:582 [inline]
do_exit+0x8b2/0x2af0 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
__do_sys_exit_group kernel/exit.c:1130 [inline]
__se_sys_exit_group kernel/exit.c:1128 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1128
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: 0033:0x7f64fc99ce59
Code: Unable to access opcode bytes at 0x7f64fc99ce2f.
RSP: 002b:00007ffc33932ae8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f64fc99ce59
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc33932b4c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000021b
R13: 00000000000927c0 R14: 0000000000133c08 R15: 00007ffc33932ba0
rcu: rcu_preempt kthread starved for 10500 jiffies! g116369 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: 13 Comm: kworker/u8:1 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+0x5a6/0x1700 kernel/smp.c:892
Code: 01 c5 41 83 c4 03 e8 39 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 c3 7d 0c 00 45 85 f6 75 d0 e8 09 83 0c 00 e8 04 83 0c 00
RSP: 0018:ffffc90000127870 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81fc2bcd
RDX: ffff88801e2b8000 RSI: ffffffff81fc2ba7 RDI: 0000000000000000
RBP: ffff8880b8540f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81e9 R14: 0000000000000001 R15: ffff8880b843c5c0
FS: 0000000000000000(0000) GS:ffff88812436d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c323057 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:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
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