rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=729c/1/0x4000000000000000 softirq=118354/118354 fqs=2
rcu: (detected by 1, t=10502 jiffies, g=92973, q=338 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 22063 Comm: syz.4.5905 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:229 [inline]
RIP: 0010:mark_lock+0x4e/0x610 kernel/locking/lockdep.c:4731
Code: 83 fa 09 0f 87 8d 00 00 00 49 89 ff 49 89 f4 89 d3 83 fa 08 74 6d 41 bd 01 00 00 00 89 d9 41 d3 e5 4d 63 ed 41 0f b7 44 24 20 <66> 25 ff 1f 0f b7 c0 48 0f a3 05 c3 d9 0f 14 0f 83 86 00 00 00 48
RSP: 0018:ffffc90000007b90 EFLAGS: 00000006
RAX: 0000000000004d10 RBX: 0000000000000008 RCX: 0000000000000008
RDX: 0000000000000008 RSI: ffff8880604054a8 RDI: ffff888060404900
RBP: ffffc90000007c30 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000078 R11: 0000000000000001 R12: ffff8880604054a8
R13: 0000000000000100 R14: 0000000000000003 R15: ffff888060404900
FS: 00007f527167a6c0(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c25a463 CR3: 00000000460be000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x3e9/0x1c90 kernel/locking/lockdep.c:5191
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:929
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
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: e9 6d 23 5d 00 be 03 00 00 00 5b e9 52 da e7 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 38 c8 e4 11 65 8b 05 49 c8 e4 11 a9 00 01 ff 00 74 1d
RSP: 0018:ffffc900051ff6f0 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000050c5b027 RCX: ffffffff820b1e6d
RDX: ffff888060404900 RSI: ffffffff820b2076 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffc900051ff9a0
R13: ffff88803606f140 R14: 0000000000000027 R15: 0000000000000000
pte_write arch/x86/include/asm/pgtable.h:218 [inline]
set_pte_range+0x336/0x740 mm/memory.c:5432
finish_fault+0xa4f/0x13e0 mm/memory.c:5580
do_read_fault mm/memory.c:5720 [inline]
do_fault mm/memory.c:5850 [inline]
do_pte_missing+0xf77/0x3ba0 mm/memory.c:4362
handle_pte_fault mm/memory.c:6195 [inline]
__handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6336
handle_mm_fault+0x589/0xd10 mm/memory.c:6505
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x54e/0x3530 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x1d8/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3478 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f527078f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f527167a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f52709e5fa0 RCX: 00007f527078f749
RDX: b635773f07ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f5270813f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52709e6038 R14: 00007f52709e5fa0 R15: 00007fffbb6dd138
rcu: rcu_preempt kthread starved for 10498 jiffies! g92973 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:28136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 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: 1 UID: 0 PID: 21566 Comm: kworker/u8:10 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:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe02/0x1600 kernel/smp.c:877
Code: 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 b5 0c 0c 00 f3 90 41 0f b6 45 00 <40> 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31 ff 83 e0 01 41
RSP: 0018:ffffc9000c67f878 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8442840 RCX: ffffffff81b0db41
RDX: ffff88805ecda480 RSI: ffffffff81b0db1b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed1017088509 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc06c1156c0 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline]
smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2923
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x376/0x550 kernel/jump_label.c:919
static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:852 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:844
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245