rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=929c/1/0x4000000000000000 softirq=49373/49373 fqs=0
rcu: (detected by 1, t=10506 jiffies, g=59729, q=655 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5609 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
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_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5864 [inline]
RIP: 0010:lock_acquire+0x166/0x370 kernel/locking/lockdep.c:5825
Code: bd 00 00 00 65 8b 05 49 35 4f 12 85 c0 0f 85 ae 00 00 00 65 48 8b 05 81 ee 4e 12 8b 90 9c 0b 00 00 85 d2 0f 85 98 00 00 00 9c <8f> 04 24 fa 48 c7 c7 ea 08 25 8e e8 ba d9 b7 09 45 89 e8 44 89 e1
RSP: 0018:ffffc90000007e08 EFLAGS: 00000046
RAX: ffff88807c11a540 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8b9fc3e6 RDI: ffffed1017085083
RBP: ffff8880b8428418 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS: 000055559422a500(0000) GS:ffff8881240e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc841f456b8 CR3: 000000005b67a000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174
__run_hrtimer kernel/time/hrtimer.c:2036 [inline]
__hrtimer_run_queues+0x1b7/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:debug_lockdep_rcu_enabled+0x20/0x40 kernel/rcu/update.c:320
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 05 6e e1 5e 05 85 c0 74 20 8b 05 20 14 5f 05 85 c0 74 16 65 48 8b 05 c8 2d 97 08 <8b> 80 9c 0b 00 00 85 c0 0f 94 c0 0f b6 c0 e9 fd 3e 03 00 66 2e 0f
RSP: 0018:ffffc900035ff320 EFLAGS: 00000202
RAX: ffff88807c11a540 RBX: ffffc900035ff6f8 RCX: ffffffff91aad301
RDX: ffffc900035ff700 RSI: 0000000000000001 RDI: ffffc900035ff3a8
RBP: 0000000000000001 R08: ffffffff91aad3ba R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000179c4 R12: ffffc900035ff3e8
R13: ffffc900035ff398 R14: ffffc900035ff6f8 R15: ffffc900035ff3cc
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x3a8/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4959
anon_vma_chain_alloc mm/rmap.c:142 [inline]
anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
dup_mmap+0x143e/0x21b0 mm/mmap.c:1803
dup_mm kernel/fork.c:1538 [inline]
copy_mm kernel/fork.c:1590 [inline]
copy_process+0x4588/0x8030 kernel/fork.c:2288
kernel_clone+0x176/0x9d0 kernel/fork.c:2747
__do_sys_clone+0xd9/0x120 kernel/fork.c:2888
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8411c58d2
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:00007ffd601ef100 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd601ef100 RCX: 00007fc8411c58d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd601ef28c R08: 0000000000000000 R09: 0000000000000001
R10: 000055559422a7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000793fa R15: 00007ffd601ef2e0
rcu: rcu_preempt kthread starved for 10506 jiffies! g59729 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
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: 1 UID: 0 PID: 3367 Comm: kworker/u8:11 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x593/0x16c0 kernel/smp.c:892
Code: 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 b9 95 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 <84> c0 0f 85 2c 0f 00 00 8b 45 08 31 ff 83 e0 01 41 89 c6 89 c6 e8
RSP: 0018:ffffc9000e22f878 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fcea8d
RDX: ffff888034600000 RSI: ffffffff81fcea67 RDI: ffff888034600000
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000000000000000(0000) GS:ffff8881241e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17deb456b8 CR3: 000000000e792000 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:911 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:903
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
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