rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=6014/1/0x4000000000000000 softirq=91491/91496 fqs=0
(detected by 0, t=10506 jiffies, g=116909, q=97 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3637 Comm: udevd Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_acquire+0xff9/0x7c50 kernel/locking/lockdep.c:-1
Code: ff 1f 00 00 41 c1 ec 03 41 81 e4 00 60 00 00 41 09 c4 4c 89 ee 48 c1 ee 20 89 f0 c1 c0 04 41 29 f4 44 31 e0 44 01 ee 41 29 c5 <89> c1 c1 c1 06 44 31 e9 01 f0 89 ca c1 c2 08 29 ce 31 f2 01 c1 29
RSP: 0018:ffffc900001e08c0 EFLAGS: 00000006
RAX: 00000000fffff030 RBX: 00000000000e4fe2 RCX: ffffffff8162fcc6
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: ffffffff90add438
RBP: ffffc900001e0b10 R08: dffffc0000000000 R09: fffffbfff215ba88
R10: fffffbfff215ba88 R11: 1ffffffff215ba87 R12: 0000000000000fcf
R13: 0000000000000fcf R14: ffff88807c464660 R15: ffff88807c4646a8
FS: 00007f9e1b36b880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e1abb5000 CR3: 000000002eaf8000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0x47/0x970 net/sched/sch_taprio.c:700
__run_hrtimer kernel/time/hrtimer.c:1752 [inline]
__hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1816
hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
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:get_lock_parent_ip include/linux/ftrace.h:-1 [inline]
RIP: 0010:preempt_latency_start kernel/sched/core.c:5691 [inline]
RIP: 0010:preempt_count_add+0x91/0x190 kernel/sched/core.c:5716
Code: b6 c0 3d f5 00 00 00 73 58 65 8b 05 f1 c1 aa 7e 25 ff ff ff 7f 39 f8 75 42 48 8b 5c 24 18 48 89 df e8 e3 6c 0c 00 85 c0 74 09 <31> db 31 ff e8 d6 6c 0c 00 65 4c 8b 35 be c1 aa 7e 49 81 c6 d8 14
RSP: 0018:ffffc90003287738 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8a20367e RCX: ffffffff96be4101
RDX: ffff88807c463b80 RSI: 0000000043e147e7 RDI: ffffffff8a20367e
RBP: ffff8880272898f8 R08: dffffc0000000000 R09: fffff52000083e15
R10: fffff52000083e15 R11: 1ffff92000083e14 R12: ffffffff81e503cb
R13: ffffc90003287c30 R14: 0000000043e147e7 R15: dffffc0000000000
__raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock+0xe/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__d_lookup+0x263/0x7c0 fs/dcache.c:2495
lookup_fast+0x7c/0x4d0 fs/namei.c:1648
walk_component fs/namei.c:1994 [inline]
link_path_walk+0x5f2/0xe50 fs/namei.c:2325
path_openat+0x276/0x2e70 fs/namei.c:3779
do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
do_sys_openat2+0x142/0x490 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9e1ad15c3a
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:00007fff0ac02d58 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055a80912ac10 RCX: 00007f9e1ad15c3a
RDX: 0000000000090800 RSI: 000055a8090fe6a0 RDI: 00000000ffffff9c
RBP: 000055a8090fe6a0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 000055a80910e7c0
R13: 00000000000000ff R14: 000055a7d7fcebe0 R15: 00007fff0ac02fe0
rcu: rcu_preempt kthread starved for 10506 jiffies! g116909 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:27904 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 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 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:rep_nop 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:424 [inline]
RIP: 0010:smp_call_function_many_cond+0xe79/0x1270 kernel/smp.c:998
Code: 85 80 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 0a 00 eb 37 90 41 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 ce
RSP: 0018:ffffc90000107800 EFLAGS: 00000293
RAX: ffffffff8175f112 RBX: dffffc0000000000 RCX: ffff88813fec3b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000107960 R08: dffffc0000000000 R09: fffffbfff215ba49
R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 1ffff110171e81c1
R13: ffff8880b8e3bb40 R14: 0000000000000001 R15: ffff8880b8f40e08
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555b0ed808 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
text_poke_bp_batch+0x2b0/0x7d0 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+0xb4/0x430 mm/kfence/core.c:805
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295