rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (207 ticks this GP) idle=c404/1/0x4000000000000000 softirq=117667/117668 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P28491/1:b..l
(detected by 0, t=10506 jiffies, g=187837, q=1045 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 28541 Comm: syz.6.6665 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:444 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1030 [inline]
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0xc0/0x920 kernel/locking/lockdep.c:5673
Code: 0f 85 c7 05 00 00 3b 1d be 2c bb 0c 0f 83 3a 05 00 00 41 89 de c1 eb 06 48 8d 3c dd e8 fb 1f 8e be 08 00 00 00 e8 30 c3 6e 00 <4c> 0f a3 35 90 2a bb 0c 73 0d e8 c1 af 07 00 84 c0 0f 84 41 05 00
RSP: 0018:ffffc900001e0b80 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8164d150
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e1ffbe8
RBP: ffffc900001e0c90 R08: ffffffff8e1ffbef R09: 1ffffffff1c3ff7d
R10: dffffc0000000000 R11: fffffbfff1c3ff7e R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff9200003c17c
FS: 00007f631e1e86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2eb1fff8 CR3: 0000000044e65000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x6d/0x120 kernel/locking/spinlock.c:194
__run_hrtimer kernel/time/hrtimer.c:1743 [inline]
__hrtimer_run_queues+0x432/0xd50 kernel/time/hrtimer.c:1811
hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 7f ee 20 f7 65 8b 05 80 60 ca 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000550fb80 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 2448a4ac7e81c300
RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: 0000000000000001
RBP: ffffc9000550fc10 R08: ffffffff90afa247 R09: 1ffffffff215f448
R10: dffffc0000000000 R11: fffffbfff215f449 R12: dffffc0000000000
R13: ffff8880b8f2a5c0 R14: ffff8880b8f2a5c0 R15: 1ffff92000aa1f70
clock_was_set+0x18f/0x9a0 kernel/time/hrtimer.c:991
do_settimeofday64+0x5b6/0x760 kernel/time/timekeeping.c:1345
__do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline]
__x64_sys_clock_settime+0x25a/0x2a0 kernel/time/posix-timers.c:1113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f631d39ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f631e1e8028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f631d615fa0 RCX: 00007f631d39ce59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f631d432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f631d616038 R14: 00007f631d615fa0 R15: 00007ffcc3b6e4a8
task:syz.0.6652 state:R running task stack:25776 pid:28491 ppid:15606 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:rol32 include/linux/bitops.h:127 [inline]
RIP: 0010:jhash2 include/linux/jhash.h:129 [inline]
RIP: 0010:hash_stack lib/stackdepot.c:276 [inline]
RIP: 0010:__stack_depot_save+0x84/0x460 lib/stackdepot.c:444
Code: f5 75 83 ff 04 72 7c 89 e9 89 ea 4c 89 f6 03 16 03 4e 04 03 6e 08 41 89 e8 41 c1 c0 04 29 ea 41 31 d0 01 cd 44 29 c1 45 89 c1 <41> c1 c1 06 41 31 c9 41 01 e8 45 89 ca 41 c1 c2 08 44 29 cd 41 31
RSP: 0018:ffffc900052f6eb8 EFLAGS: 00000a83
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000f1ccecf4
RDX: 00000000fffff769 RSI: ffffc900052f6f60 RDI: 0000000000000020
RBP: 000000006db2e920 R08: 0000000084288506 R09: 0000000084288506
R10: dffffc0000000000 R11: fffff52000a5edc9 R12: 0000000000002800
R13: 0000000000000001 R14: ffffc900052f6f60 R15: 0000000000000010
save_stack+0x12f/0x230 mm/page_owner.c:128
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1486 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3554
release_pages+0x1fa6/0x2220 mm/swap.c:1035
__pagevec_release+0x6d/0xe0 mm/swap.c:1055
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x7c2/0x20c0 mm/shmem.c:946
shmem_truncate_range mm/shmem.c:1062 [inline]
shmem_evict_inode+0x25b/0xa80 mm/shmem.c:1171
evict+0x4c9/0x8d0 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfa/0x1d0 fs/dcache.c:918
__fput+0x5e0/0x920 fs/file_table.c:328
task_work_run+0x1d0/0x260 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x982/0x2480 kernel/exit.c:881
do_group_exit+0x217/0x2d0 kernel/exit.c:1023
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa1b699ce59
RSP: 002b:00007fa1b7787028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fa1b6c16090 RCX: 00007fa1b699ce59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fa1b6a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa1b6c16128 R14: 00007fa1b6c16090 R15: 00007ffd70975458
rcu: rcu_preempt kthread timer wakeup didn't happen for 10344 jiffies! g187837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=109944
rcu: rcu_preempt kthread starved for 10345 jiffies! g187837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27760 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0xea2/0x1290 kernel/smp.c:998
Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 f6 f6 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 82 f3 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 67 f3 0a
RSP: 0000:ffffc90000107800 EFLAGS: 00000293
RAX: ffffffff81779349 RBX: dffffc0000000000 RCX: ffff88813fe73b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000107960 R08: ffffffff90afa247 R09: 1ffffffff215f448
R10: dffffc0000000000 R11: fffffbfff215f449 R12: 1ffff110171e81d9
R13: ffff8880b8e3bbc0 R14: 0000000000000001 R15: ffff8880b8f40ec8
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f045dc5c63d CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774
text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207
static_key_enable+0x16/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295