rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=fe2c/1/0x4000000000000000 softirq=85332/85332 fqs=1
rcu: (detected by 0, t=10502 jiffies, g=103641, q=175 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7843 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:preempt_latency_start kernel/sched/core.c:5826 [inline]
RIP: 0010:preempt_count_add+0x80/0x1a0 kernel/sched/core.c:5852
Code: e6 00 00 00 83 3d 0f b8 d0 15 00 75 11 65 8b 05 ce 29 a7 7e 0f b6 c0 3d f5 00 00 00 73 58 65 8b 05 bd 29 a7 7e 25 ff ff ff 7f <39> f8 75 42 48 8b 5c 24 18 48 89 df e8 5f e4 0c 00 85 c0 74 09 31
RSP: 0018:ffffc900001f0be0 EFLAGS: 00000002
RAX: 0000000000010004 RBX: ffffffff975336c8 RCX: ffffffff972d4403
RDX: 0000000000000008 RSI: ffffffff8acadd60 RDI: 0000000000000001
RBP: ffffc900001f0c90 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000802 R15: dffffc0000000000
FS: 000055558564d500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c365d53 CR3: 000000002d5d4000 CR4: 00000000003506e0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:109 [inline]
_raw_spin_lock_irqsave+0x99/0x100 kernel/locking/spinlock.c:162
debug_object_activate+0x6c/0x4f0 lib/debugobjects.c:709
debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
debug_activate kernel/time/hrtimer.c:504 [inline]
enqueue_hrtimer+0x34/0x380 kernel/time/hrtimer.c:1100
__run_hrtimer kernel/time/hrtimer.c:1771 [inline]
__hrtimer_run_queues+0x63c/0xc40 kernel/time/hrtimer.c:1818
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__page_table_check_ptes_set+0x245/0x300 mm/page_table_check.c:225
Code: 9c ff 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 6f cb 9c ff b3 01 0f b6 d3 4c 89 f7 4c 89 fe 48 83 c4 18 5b 41 5c 41 5d <41> 5e 41 5f 5d e9 b1 00 00 00 49 89 dc 48 d1 eb 49 bf 00 00 00 00
RSP: 0018:ffffc9000353f500 EFLAGS: 00000286
RAX: ffffffff81ea6021 RBX: ffff8880312e4c00 RCX: ffff88801eea9e00
RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000000641ce
RBP: 0000000000000000 R08: ffffea0001907387 R09: 1ffffd4000320e70
R10: dffffc0000000000 R11: fffff94000320e71 R12: 00007f6cab1ae000
R13: dffffc0000000000 R14: 00000000000641ce R15: 0000000000000001
page_table_check_ptes_set include/linux/page_table_check.h:74 [inline]
set_ptes include/linux/pgtable.h:238 [inline]
copy_present_pte mm/memory.c:979 [inline]
copy_pte_range mm/memory.c:1083 [inline]
copy_pmd_range mm/memory.c:1168 [inline]
copy_pud_range mm/memory.c:1205 [inline]
copy_p4d_range mm/memory.c:1229 [inline]
copy_page_range+0x24e5/0x3670 mm/memory.c:1323
dup_mmap kernel/fork.c:769 [inline]
dup_mm kernel/fork.c:1694 [inline]
copy_mm+0x1281/0x1d80 kernel/fork.c:1743
copy_process+0x16f7/0x3dc0 kernel/fork.c:2508
kernel_clone+0x24b/0x8a0 kernel/fork.c:2917
__do_sys_clone kernel/fork.c:3060 [inline]
__se_sys_clone kernel/fork.c:3044 [inline]
__x64_sys_clone+0x1b7/0x230 kernel/fork.c:3044
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6cabfc58d2
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffdb2ed4d90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffdb2ed4d90 RCX: 00007f6cabfc58d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffdb2ed4f1c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558564d7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000d9413 R15: 00007ffdb2ed4f70
rcu: rcu_preempt kthread starved for 10495 jiffies! g103641 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:26568 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 60 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfe/0x1140 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4b f7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 86 f3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 6a f3
RSP: 0018:ffffc900015b7780 EFLAGS: 00000293
RAX: ffffffff817c3826 RBX: 1ffff110171e827d RCX: ffff88801e6a8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900015b7900 R08: ffffffff911cd507 R09: 1ffffffff2239aa0
R10: dffffc0000000000 R11: fffffbfff2239aa1 R12: ffff8880b8f413e8
R13: dffffc0000000000 R14: ffff8880b8e3d1c8 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c38b013 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x31e/0x990 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xa8/0x260 mm/kfence/core.c:847
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293