rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13743/1:b..l
rcu: (detected by 1, t=10504 jiffies, g=63309, q=251 ncpus=2)
task:cmp state:R running task stack:24488 pid:13743 tgid:13743 ppid:13720 task_flags:0x40000c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7189
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
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 db 6a f4 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:ffffc9000f20f458 EFLAGS: 00000206
RAX: a7a456859e84b300 RBX: 0000000000000000 RCX: a7a456859e84b300
RDX: 0000000000000000 RSI: ffffffff8da159c5 RDI: ffffffff8bc07ce0
RBP: ffffffff8173df15 R08: 0000000000000000 R09: ffffffff8173df15
R10: ffffc9000f20f618 R11: ffffffff81ac9fd0 R12: 0000000000000002
R13: ffffffff8e13d720 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5755
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2482 [inline]
slab_free mm/slub.c:6619 [inline]
kmem_cache_free+0x16f/0x690 mm/slub.c:6729
exit_mmap+0x537/0xb40 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ce02b46c5
RSP: 002b:00007fff072e5d88 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f2ce03b5fe8 RCX: 00007f2ce02b46c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007fff072e5d18 R09: 0000000000000000
R10: 00007fff072e5bb0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2ce03b4680 R15: 00007f2ce03b6000
rcu: rcu_preempt kthread starved for 10501 jiffies! g63309 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
__schedule_loop kernel/sched/core.c:6944 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6959
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 12614 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 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 45 6f
RSP: 0018:ffffc900161f7640 EFLAGS: 00000293
RAX: ffffffff81b507cb RBX: 1ffff110170c8449 RCX: ffff888025763c80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900161f77c0 R08: ffffffff8f9e3577 R09: 1ffffffff1f3c6ae
R10: dffffc0000000000 R11: fffffbfff1f3c6af R12: ffff8880b8642248
R13: dffffc0000000000 R14: ffff8880b873b240 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125dfd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31512ff8 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2697 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2907
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:852
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245