rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (13 ticks this GP) idle=58d/1/0x4000000000000000 softirq=84405/84405 fqs=9
(detected by 0, t=10502 jiffies, g=127273, q=277)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 26782 Comm: syz.2.5624 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:check_preemption_disabled+0x4b/0x110 lib/smp_processor_id.c:55
Code: 0d e2 85 45 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 74
RSP: 0018:ffffc90000dd0b50 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5727e49120fd3400
RDX: 0000000000000000 RSI: ffffffff8a2b43a0 RDI: ffffffff8a7a0700
RBP: ffffc90000dd0c80 R08: dffffc0000000000 R09: 1ffffffff203ac18
R10: dffffc0000000000 R11: fffffbfff203ac19 R12: ffffffff8c31f320
R13: 1ffff920001ba178 R14: 0000000000000046 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fa15ff8 CR3: 000000000c08e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
lock_acquire+0x1ae/0x400 kernel/locking/lockdep.c:5625
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
advance_sched+0x6ca/0x940 net/sched/sch_taprio.c:769
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_count_add+0x66/0x190 kernel/sched/core.c:5512
Code: af 7e 48 c7 c0 80 cf 2d 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e6 00 00 00 83 3d 23 5d db 14 00 75 11 65 8b 05 62 fd af 7e <0f> b6 c0 3d f5 00 00 00 73 58 65 8b 05 51 fd af 7e 25 ff ff ff 7f
RSP: 0018:ffffc9000302ed88 EFLAGS: 00000246
RAX: 0000000080000001 RBX: ffffc9000302ee68 RCX: ffffffff962dcf03
RDX: dffffc0000000000 RSI: ffffffff8167ae86 RDI: 0000000000000001
RBP: ffffc9000302eeb0 R08: ffffc9000302ef30 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000605dd9 R12: ffffffff8167ae86
R13: ffffc9000302ef00 R14: dffffc0000000000 R15: dffffc0000000000
unwind_next_frame+0xac/0x1d90 arch/x86/kernel/unwind_orc.c:433
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
save_stack+0x121/0x230 mm/page_owner.c:119
__reset_page_owner+0x51/0x180 mm/page_owner.c:140
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
release_pages+0x186c/0x1be0 mm/swap.c:963
__pagevec_release+0x6d/0xe0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x62b/0x1930 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
evict+0x4c9/0x8d0 fs/inode.c:647
__dentry_kill+0x431/0x650 fs/dcache.c:586
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x5ee/0x930 fs/file_table.c:319
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:884
do_group_exit+0x12e/0x300 kernel/exit.c:998
get_signal+0x6d6/0x12d0 kernel/signal.c:2900
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd6a3b01e59
Code: Unable to access opcode bytes at RIP 0x7fd6a3b01e2f.
RSP: 002b:00007fd6a1d5b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd6a3d7afa8 RCX: 00007fd6a3b01e59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd6a3d7afa8
RBP: 00007fd6a3d7afa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd6a3d7b038 R14: 00007fffcc328d20 R15: 00007fffcc328e08
rcu: rcu_preempt kthread starved for 10484 jiffies! g127273 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:28112 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 26806 Comm: syz.3.5631 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xbb5/0xd90 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 d9 62 0b 00 83 e3 01 75 07 e8 6f 5f 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc9000306fae0 EFLAGS: 00000246
RAX: ffffffff816dd6c8 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc900110bf000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000306fc10 R08: ffff8880b903b3d7 R09: 1ffff1101720767a
R10: dffffc0000000000 R11: ffffed101720767b R12: ffff8880b91405c8
R13: 1ffff110172280b9 R14: ffff8880b903b3c0 R15: 0000000000000001
clock_was_set+0x781/0x850 kernel/time/hrtimer.c:959
do_settimeofday64+0x5b6/0x760 kernel/time/timekeeping.c:1328
__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:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f33312e7e59
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:00007f332f520028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f3331561090 RCX: 00007f33312e7e59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f333137dd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3331561128 R14: 00007f3331561090 R15: 00007ffeea495578