rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 ticks this GP) idle=0c64/1/0x4000000000000000 softirq=79763/79772 fqs=3
rcu: (detected by 0, t=10502 jiffies, g=61289, q=452 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12774 Comm: syz.0.1488 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:_raw_spin_lock_irqsave+0x4f/0x60 kernel/locking/spinlock.c:166
Code: 8d 7e 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 74 24 10 e8 a0 56 f4 f5 48 83 c4 08 4c 89 f7 e8 34 f8 f4 f5 48 89 d8 <5b> 41 5e e9 94 c6 62 f5 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90000a08d50 EFLAGS: 00000046
RAX: 0000000000000096 RBX: 0000000000000096 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a08cc0
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141198 R12: ffff88802b6f2300
R13: dffffc0000000000 R14: ffffffff9a725050 R15: ffffffff9a725048
FS: 00007fa725b076c0(0000) GS:ffff88812536a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa725b06ff8 CR3: 0000000075b72000 CR4: 0000000000350ef0
Call Trace:
debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:928
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:2000 [inline]
__hrtimer_run_queues+0x239/0xa10 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+0xa1/0xc0 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 6d fb f4 f5 f7 c3 00 02 00 00 74 05 e8 30 d2 20 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 12 e6 f5 65 8b 05 2d e4 8d 07 85 c0 74 18 5b 41 5e e9 fc c4
RSP: 0018:ffffc90002ea76a8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000286 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8c292100 RDI: 0000000000000001
RBP: ffff888054943a40 R08: ffffffff903142f7 R09: 1ffffffff206285e
R10: dffffc0000000000 R11: fffffbfff206285f R12: 0000000000000000
R13: 0000000000000001 R14: ffff888054943a00 R15: ffff888054943a40
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
__wake_up_common_lock+0x195/0x1f0 kernel/sched/wait.c:127
__unix_dgram_recvmsg+0x488/0xd70 net/unix/af_unix.c:2607
sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1126
____sys_recvmsg+0x3e3/0x4a0 net/socket.c:2902
___sys_recvmsg+0x213/0x5a0 net/socket.c:2946
do_recvmmsg+0x31a/0x7f0 net/socket.c:3041
__sys_recvmmsg net/socket.c:3115 [inline]
__do_sys_recvmmsg net/socket.c:3138 [inline]
__se_sys_recvmmsg net/socket.c:3131 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3131
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: 0033:0x7fa724b9ce59
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:00007fa725b07028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fa724e16090 RCX: 00007fa724b9ce59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fa724c32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa724e16128 R14: 00007fa724e16090 R15: 00007fffe82aadc8
rcu: rcu_preempt kthread starved for 10489 jiffies! g61289 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:28040 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
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:
CPU: 0 UID: 0 PID: 48 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b5/0x14b0 kernel/smp.c:892
Code: 1e 89 de 83 e6 01 31 ff e8 28 1d 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 d4 18 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 b9 18 0c 00 eb e5 44 89
RSP: 0018:ffffc90000b87720 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888020af3e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b87860 R08: ffffffff903142f7 R09: 1ffffffff206285e
R10: dffffc0000000000 R11: fffffbfff206285f R12: 1ffff110170e8199
R13: ffff8880b863c2c8 R14: ffff8880b8740cc8 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812526a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa724bea540 CR3: 000000000e746000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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