rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=334c/1/0x4000000000000000 softirq=68494/68494 fqs=5
rcu: 	(detected by 1, t=10502 jiffies, g=61109, q=1079 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18605 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 03 35 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 b0 7e 92 <65> 8b 15 c8 fd bc 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90000007d10 EFLAGS: 00000002
RAX: ffffffff81af4cb9 RBX: 0000000000000001 RCX: ffff88802ce61e80
RDX: ffff88802ce61e80 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: ffffc90000007e90 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: ffff8880529de300
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b86283c0
FS:  0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9cd4e7bb4c CR3: 000000006b8b2000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 trace_hrtimer_cancel include/trace/events/timer.h:317 [inline]
 debug_deactivate+0x89/0x1e0 kernel/time/hrtimer.c:484
 __run_hrtimer kernel/time/hrtimer.c:1745 [inline]
 __hrtimer_run_queues+0x2b0/0xc30 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x524/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 <48> 0f 46 e9 49 8d 47 fc 48 0f 47 d8 4d 0f 46 ef 48 39 dd 76 a2 e9
RSP: 0018:ffffc9000e7c6ff8 EFLAGS: 00000283
RAX: ffffffff8b5bbf7a RBX: ffffffff90092954 RCX: ffffffff9009294c
RDX: ffffffff90092920 RSI: ffffffff90bc2b42 RDI: ffffffff8bc08300
RBP: ffffffff9009293c R08: 000000000000000e R09: ffffffff8df41a20
R10: ffffc9000e7c7118 R11: ffffffff81ada120 R12: ffffffff8b5bbff1
R13: ffffffff90092938 R14: ffffc9000e7c70c8 R15: ffffffff90092948
 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
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 ptlock_alloc mm/memory.c:7377 [inline]
 ptlock_init include/linux/mm.h:3280 [inline]
 pmd_ptlock_init include/linux/mm.h:3413 [inline]
 pagetable_pmd_ctor include/linux/mm.h:3441 [inline]
 pmd_alloc_one_noprof include/asm-generic/pgalloc.h:146 [inline]
 __pmd_alloc+0xc2/0x5d0 mm/memory.c:6666
 pmd_alloc include/linux/mm.h:3106 [inline]
 __handle_mm_fault mm/memory.c:6363 [inline]
 handle_mm_fault+0xe51/0x32b0 mm/memory.c:6580
 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:99
Code: c9 75 f6 e9 92 59 04 00 48 89 07 48 83 c7 08 83 e9 08 74 ef 83 f9 08 73 ef eb de 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <48> 89 07 48 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47
RSP: 0018:ffffc9000e7c78f8 EFLAGS: 00050206
RAX: 0000000000000000 RBX: 00007f9cd4e7c310 RCX: 00000000000004b4
RDX: 0000000000000000 RSI: ffffffff8d979363 RDI: 00007f9cd4e7bb4c
RBP: dffffc0000000000 R08: ffffffff820f72d0 R09: ffff88801d7d0f80
R10: dffffc0000000000 R11: ffffed10059cc3d1 R12: 00007f9cd4e7bb4c
R13: 0000000000000b4c R14: 00000000000004b4 R15: ffff888028c960a8
 __clear_user arch/x86/include/asm/uaccess_64.h:188 [inline]
 clear_user arch/x86/include/asm/uaccess_64.h:205 [inline]
 padzero fs/binfmt_elf.c:133 [inline]
 elf_load+0x4d2/0x6c0 fs/binfmt_elf.c:435
 load_elf_interp+0x4ce/0xb60 fs/binfmt_elf.c:689
 load_elf_binary+0x1a01/0x2740 fs/binfmt_elf.c:1254
 search_binary_handler fs/exec.c:1669 [inline]
 exec_binprm fs/exec.c:1701 [inline]
 bprm_execve+0x92e/0x1400 fs/exec.c:1753
 kernel_execve+0x8f0/0x9f0 fs/exec.c:1919
 call_usermodehelper_exec_async+0x210/0x360 kernel/umh.c:109
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread starved for 10492 jiffies! g61109 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:27272 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 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+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 3665 Comm: kworker/u8:12 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:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xccd/0x12b0 kernel/smp.c:877
Code: 00 00 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4a 9a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 f5 95 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
RSP: 0018:ffffc9000c9c7620 EFLAGS: 00000293
RAX: ffffffff81b61c77 RBX: 1ffff110170c856d RCX: ffff888030d08000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000c9c77a0 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faeebed6a10 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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:2711 [inline]
 smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:874
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>