rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=6eac/1/0x4000000000000000 softirq=185624/185625 fqs=3
rcu: (detected by 0, t=10502 jiffies, g=174781, q=191 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 27947 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x28d/0x3d0 kernel/locking/lockdep.c:5892
Code: 24 08 48 c7 c7 64 76 97 8d e8 4f 79 bd 09 b8 ff ff ff ff 65 0f c1 05 b2 1f d8 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c <8f> 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01
RSP: 0018:ffffc90000a08c10 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000002 RCX: ccb504e3a06fcd00
RDX: 0000000000000002 RSI: ffffffff8d977664 RDI: ffffffff8bbf7760
RBP: ffff88802a536700 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141170 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff99afe238 R15: ffff88802a535b80
FS: 00005555835f2500(0000) GS:ffff888125fb8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2cb93e7dac CR3: 0000000079abc000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:483
__run_hrtimer kernel/time/hrtimer.c:1745 [inline]
__hrtimer_run_queues+0x2b0/0xc70 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+0x102/0x410 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
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 3b 14 6b f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 93 83 32 f6 65 8b 05 7c de 17 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000c6af160 EFLAGS: 00000206
RAX: ccb504e3a06fcd00 RBX: 0000000000000a02 RCX: ccb504e3a06fcd00
RDX: 0000000000000006 RSI: ffffffff8d790e8f RDI: 0000000000000001
RBP: ffffc9000c6af1f0 R08: ffffffff8f7df377 R09: 1ffffffff1efbe6e
R10: dffffc0000000000 R11: fffffbfff1efbe6f R12: dffffc0000000000
R13: ffff88814e800000 R14: ffffffff99a0cdb0 R15: 1ffff920018d5e2c
__debug_check_no_obj_freed lib/debugobjects.c:1108 [inline]
debug_check_no_obj_freed+0x451/0x470 lib/debugobjects.c:1129
free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0x492/0x1470 mm/page_alloc.c:3000
folios_put_refs+0x584/0x670 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137
shmem_truncate_range mm/shmem.c:1249 [inline]
shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1381
evict+0x5f4/0xae0 fs/inode.c:837
__dentry_kill+0x209/0x660 fs/dcache.c:670
shrink_kill+0xa9/0x2c0 fs/dcache.c:1137
shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164
shrink_dcache_tree+0xca/0x2e0 fs/dcache.c:-1
do_one_tree+0x28/0xe0 fs/dcache.c:1644
shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1661
generic_shutdown_super+0x67/0x2c0 fs/super.c:621
kill_anon_super+0x3b/0x70 fs/super.c:1289
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1328
task_work_run+0x1d4/0x260 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:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc67b90a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffee795d9c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fdc67c13d7d RCX: 00007fdc67b90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffee795da80
RBP: 00007ffee795da80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffee795eb10
R13: 00007fdc67c13d7d R14: 0000000000208b3b R15: 00007ffee795eb50
rcu: rcu_preempt kthread starved for 10495 jiffies! g174781 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26808 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5030 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 16209 Comm: kworker/u8:1 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+0xccf/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 6a 9c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 98 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 f9 97
RSP: 0018:ffffc9000c977660 EFLAGS: 00000293
RAX: ffffffff81b64557 RBX: 1ffff110170e8129 RCX: ffff888028eb0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000c9777e0 R08: ffffffff8f7df377 R09: 1ffffffff1efbe6e
R10: dffffc0000000000 R11: fffffbfff1efbe6f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125eb8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000018d030 CR3: 000000000dd38000 CR4: 00000000003526f0
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: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+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:854
process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
process_scheduled_works kernel/workqueue.c:3344 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
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