rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10506 jiffies, g=184701, q=402 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4295106546-4295096040), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10506 jiffies! g184701 f0x2 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4972 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:advance_sched+0x240/0xc80 net/sched/sch_taprio.c:947
Code: 00 48 89 44 24 18 74 0f 48 8b 7c 24 18 e8 88 76 58 f8 48 8b 44 24 18 48 8b 28 48 83 3c 24 00 0f 84 0b 01 00 00 e8 40 da ea f7 <4d> 85 ff 0f 84 52 01 00 00 48 89 6c 24 20 49 8d 9f 50 01 00 00 48
RSP: 0018:ffffc90000a089f8 EFLAGS: 00000006
RAX: ffffffff89dc2720 RBX: ffff88807e9f62f0 RCX: ffff88807f0e0000
RDX: 0000000000010100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141130 R12: 0000000000000000
R13: ffff88807e9f6000 R14: dffffc0000000000 R15: ffff88808194a400
FS: 00007f23a0441880(0000) GS:ffff888125055000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007effea8e9e9c CR3: 000000007eaaf000 CR4: 0000000000350ef0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 2d ed cf f5 f7 c3 00 02 00 00 74 05 e8 90 cd fb f5 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 c4 00 c1 f5 65 8b 05 bd 40 99 07 85 c0 74 18 5b 41 5e e9 8c d1
RSP: 0018:ffffc90000a08da8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000296 RCX: 0000000000000101
RDX: 0000000000000003 RSI: ffffffff8e228edb RDI: 0000000000000001
RBP: ffffc90000a08f20 R08: ffffffff90574837 R09: 1ffffffff20ae906
R10: dffffc0000000000 R11: fffffbfff20ae907 R12: ffff88802a0e89c0
R13: dffffc0000000000 R14: ffffffff9aa28ef0 R15: 0000000000000006
debug_rcu_head_unqueue kernel/rcu/rcu.h:245 [inline]
rcu_do_batch kernel/rcu/tree.c:2637 [inline]
rcu_core+0x6f7/0x10a0 kernel/rcu/tree.c:2897
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:trace_lock_release include/trace/events/lock.h:68 [inline]
RIP: 0010:lock_release+0x4b/0x3c0 kernel/locking/lockdep.c:5879
Code: 89 44 24 28 0f 1f 44 00 00 65 8b 05 f3 c8 c9 11 83 f8 08 0f 83 56 02 00 00 89 c0 48 0f a3 05 dc 60 b4 0e 73 0d e8 25 f9 08 00 <84> c0 0f 84 94 02 00 00 83 3d d6 93 b4 0e 00 0f 84 1c 02 00 00 65
RSP: 0018:ffffc9000450f900 EFLAGS: 00000212
RAX: 0000000000000001 RBX: ffffffff8274c30c RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8c4bbf60 RDI: ffffffff8c4bbf20
RBP: 0000000000000001 R08: ffffffff8274c30c R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffffff8274c30c R14: ffffffff8eb59c60 R15: ffff888026e893c0
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
kernfs_root+0x1e5/0x230 fs/kernfs/kernfs-internal.h:81
kernfs_active fs/kernfs/dir.c:40 [inline]
kernfs_dop_revalidate+0xd5/0x650 fs/kernfs/dir.c:1220
d_revalidate fs/namei.c:1035 [inline]
lookup_fast+0x25d/0x5d0 fs/namei.c:-1
lookup_fast_for_open fs/namei.c:4545 [inline]
open_last_lookups fs/namei.c:4579 [inline]
path_openat+0x603/0x3830 fs/namei.c:4860
do_file_open+0x23e/0x4a0 fs/namei.c:4892
do_sys_openat2+0x115/0x200 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f239fd15c3a
Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24
RSP: 002b:00007ffe4378ad28 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055945f6ee410 RCX: 00007f239fd15c3a
RDX: 0000000000090800 RSI: 000055945f6c2a10 RDI: 00000000ffffff9c
RBP: 000055945f6c2a10 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 000055945f6c47b0
R13: 00000000000000ff R14: 000055943c25bbe0 R15: 00007ffe4378afc0