rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11173/1:b..l
(detected by 1, t=10502 jiffies, g=48989, q=351 ncpus=2)
task:syz.1.1669 state:R running task stack:25824 pid:11173 ppid:4265 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__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:1459 [inline]
free_pcp_prepare mm/page_alloc.c:1509 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
release_pages+0x1f92/0x2200 mm/swap.c:1035
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
tlb_flush_mmu+0xff/0x210 mm/mmu_gather.c:261
tlb_finish_mmu+0xbd/0x1c0 mm/mmu_gather.c:361
exit_mmap+0x343/0x8e0 mm/mmap.c:3258
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 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:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9c9a18eb69
RSP: 002b:00007f9c9b0b40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f9c9a3b5fa8 RCX: 00007f9c9a18eb69
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f9c9a3b5fac
RBP: 00007f9c9a3b5fa0 R08: 0022d8c07bc184a3 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9c9a3b5fac
R13: 0000000000000000 R14: 00007ffdd90c7da0 R15: 00007ffdd90c7e88
rcu: rcu_preempt kthread timer wakeup didn't happen for 10498 jiffies! g48989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=38468
rcu: rcu_preempt kthread starved for 10504 jiffies! g48989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28000 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: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 87 9e 0c 48 89 de 5b e9 87 53 4f 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 54 a8 81 7e 65 8b 15 55 a8 81 7e 81 e2 00
RSP: 0018:ffffc900001dff58 EFLAGS: 00000293
RAX: ffffffff885042c6 RBX: 00000000000007f0 RCX: 0000000000000100
RDX: ffff888017739dc0 RSI: 00000000000003f7 RDI: 0000000000000fff
RBP: 00000000000003f7 R08: dffffc0000000000 R09: fffffbfff215ba69
R10: fffffbfff215ba69 R11: 1ffffffff215ba68 R12: 0000000000000000
R13: 00000000000003f7 R14: 00000000000003f7 R15: ffff8880462c71a4
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c32ebe3 CR3: 000000004751d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
cake_heap_get_backlog net/sched/sch_cake.c:1470 [inline]
cake_heapify+0x1dd/0x6a0 net/sched/sch_cake.c:1495
cake_drop net/sched/sch_cake.c:1575 [inline]
cake_enqueue+0x305a/0x7ee0 net/sched/sch_cake.c:1945
qdisc_enqueue include/net/sch_generic.h:816 [inline]
netem_dequeue+0xcfc/0x13c0 net/sched/sch_netem.c:737
dequeue_skb net/sched/sch_generic.c:292 [inline]
qdisc_restart net/sched/sch_generic.c:397 [inline]
__qdisc_run+0x247/0x15f0 net/sched/sch_generic.c:415
__dev_xmit_skb net/core/dev.c:3958 [inline]
__dev_queue_xmit+0x107e/0x3760 net/core/dev.c:4300
dev_queue_xmit include/linux/netdevice.h:3051 [inline]
tipc_l2_send_msg+0x30f/0x3d0 net/tipc/bearer.c:518
tipc_bearer_xmit_skb+0x2a9/0x3f0 net/tipc/bearer.c:577
tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1549 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1820
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 e9 e8 04 00 00 4c 8b 75 d0 4c 89 e7 e8 20 c7 c7 08 e8 0b b1 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90000177bd8 EFLAGS: 00000286
RAX: 491fe3289926e600 RBX: 0000000000000000 RCX: 491fe3289926e600
RDX: dffffc0000000000 RSI: ffffffff8a8c0460 RDI: ffffffff8adef320
RBP: ffffc90000177c30 R08: dffffc0000000000 R09: ffffed10171c7551
R10: ffffed10171c7551 R11: 1ffff110171c7550 R12: ffff888017739dc0
R13: dffffc0000000000 R14: ffff88807da21dc0 R15: ffff8880b8f3b550
context_switch kernel/sched/core.c:5247 [inline]
__schedule+0x10f4/0x40b0 kernel/sched/core.c:6561
schedule_idle+0x4a/0x90 kernel/sched/core.c:6665
do_idle+0x525/0x570 kernel/sched/idle.c:331
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
secondary_startup_64_no_verify+0xcf/0xdb