rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5622/1:b..l P8884/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=40205, q=300 ncpus=2)
task:syz.1.673 state:R running task stack:24296 pid:8884 tgid:8882 ppid:5628 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
RIP: 0010:unwind_next_frame+0xeed/0x2550 arch/x86/kernel/unwind_orc.c:614
Code: 96 c0 20 c8 3c 01 0f 85 54 0c 00 00 48 89 df e8 c9 22 00 00 48 89 c3 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 <4c> 8b 7c 24 10 74 08 4c 89 ff e8 74 02 ba 00 49 89 1f 48 8b 44 24
RSP: 0018:ffffc900044cf078 EFLAGS: 00000246
RAX: 1ffff92000899e3e RBX: ffffffff816d8353 RCX: 1ffff92000899e01
RDX: ffffffff90c51806 RSI: 0000000000000002 RDI: ffffc900044cf1a0
RBP: dffffc0000000000 R08: 0000000000000009 R09: ffffffff8e95cde0
R10: dffffc0000000000 R11: fffff52000899e41 R12: ffffc900044d0000
R13: 1ffff92000899e37 R14: ffffc900044cf1a8 R15: ffffc900044c8000
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
prep_new_page mm/page_alloc.c:1866 [inline]
get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509
shmem_alloc_folio mm/shmem.c:1933 [inline]
shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2564
shmem_get_folio mm/shmem.c:2670 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3303
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3478
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0297b5d68e
RSP: 002b:00007f0298a3cda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0298a3d6c0 RCX: 00007f0297b5d68e
RDX: 0000000001000000 RSI: 00007f028d800000 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 00007f0298a3cee0 R14: 00007f0298a3cea0 R15: 00007f028d800000
task:syz-executor state:R running task stack:21112 pid:5622 tgid:5622 ppid:5615 task_flags:0x20400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:206
spin_unlock_irq include/linux/spinlock.h:402 [inline]
loop_queue_work drivers/block/loop.c:863 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1889
__blk_mq_issue_directly block/blk-mq.c:2725 [inline]
blk_mq_request_issue_directly+0x3bb/0x6d0 block/blk-mq.c:2812
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2833
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2908
blk_mq_flush_plug_list+0x456/0x570 block/blk-mq.c:2991
__blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x28d/0x580 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
submit_bh fs/buffer.c:2742 [inline]
__sync_dirty_buffer+0x22e/0x370 fs/buffer.c:2780
nilfs_sync_super fs/nilfs2/super.c:219 [inline]
nilfs_commit_super+0x6cb/0x970 fs/nilfs2/super.c:302
nilfs_cleanup_super+0x352/0x420 fs/nilfs2/super.c:335
nilfs_put_super+0x98/0x150 fs/nilfs2/super.c:513
generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
kill_block_super+0x44/0x90 fs/super.c:1725
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f220c99e097
RSP: 002b:00007ffdc2d38fc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f220ca321ca RCX: 00007f220c99e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc2d39080
RBP: 00007ffdc2d39080 R08: 00007ffdc2d3a080 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc2d3a110
R13: 00007f220ca321ca R14: 0000000000063273 R15: 00007ffdc2d3a150
rcu: rcu_preempt kthread starved for 10490 jiffies! g40205 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:27968 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 47 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0xfcd/0x13d0 kernel/smp.c:892
Code: c0 75 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 06 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 02 0c 00 eb 37 90 43 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a
RSP: 0018:ffffc90000b77700 EFLAGS: 00000293
RAX: ffffffff81b9c256 RBX: ffff8880b873c148 RCX: ffff888022e8bd80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b77840 R08: ffffffff9030c6f7 R09: 1ffffffff20618de
R10: dffffc0000000000 R11: fffffbfff20618df R12: 1ffff110170c8589
R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f573e665ff8 CR3: 000000000e74a000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 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+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983
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+0xab/0x290 mm/kfence/core.c:906
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245