rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3855/1:b..l P21/1:b..l
(detected by 1, t=10502 jiffies, g=11189, q=122)
task:kworker/1:0 state:R running task stack:25840 pid: 21 ppid: 2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x196/0x1d0 include/linux/seqlock.h:106
Code: f9 4d 85 e4 75 16 e8 49 16 55 f9 eb 15 e8 42 16 55 f9 e8 cd 0c 98 01 4d 85 e4 74 ea e8 33 16 55 f9 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90000db7a20 EFLAGS: 00000293
RAX: ffffffff88240c0d RBX: 0000000000000000 RCX: ffff888017a09dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000db7ad0 R08: ffffffff901d215f R09: 1ffffffff203a42b
R10: dffffc0000000000 R11: fffffbfff203a42c R12: 0000000000000200
R13: ffff88807a219800 R14: 1ffff920001b6f44 R15: dffffc0000000000
nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline]
gc_worker+0x2e2/0x1390 net/netfilter/nf_conntrack_core.c:1472
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
task:dhcpcd state:R running task stack:21328 pid: 3855 ppid: 3854 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_acquire+0xd0/0x400 kernel/locking/lockdep.c:5596
Code: 3c c5 28 db 89 8d be 08 00 00 00 e8 fa 2d 61 00 44 89 f0 48 0f a3 05 67 d9 2c 0c 73 0d e8 a8 ce 07 00 84 c0 0f 84 2d 02 00 00 <48> c7 c0 c4 0e 8a 8d 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 1c 02
RSP: 0018:ffffc900034bf6a0 EFLAGS: 00000202
RAX: 0000000000088d01 RBX: 0000000000000000 RCX: edd8da1ad0d95a00
RDX: 0000000000000000 RSI: ffffffff8a79f720 RDI: ffffffff8a79f6e0
RBP: ffffc900034bf7a8 R08: ffffffff8d89db2f R09: 1ffffffff1b13b65
R10: dffffc0000000000 R11: fffffbfff1b13b66 R12: ffffffff8c31eaa0
R13: 1ffff92000697ee0 R14: 0000000000000000 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
sk_filter_trim_cap+0x14c/0x810 net/core/filter.c:146
sk_filter include/linux/filter.h:935 [inline]
unix_dgram_sendmsg+0xafc/0x18a0 net/unix/af_unix.c:1840
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
sock_write_iter+0x2a6/0x3a0 net/socket.c:1089
do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
do_iter_write+0x205/0x7b0 fs/read_write.c:855
vfs_writev fs/read_write.c:928 [inline]
do_writev+0x281/0x480 fs/read_write.c:971
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: 0033:0x7f3763871407
RSP: 002b:00007fff55d59520 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f37637e7740 RCX: 00007f3763871407
RDX: 0000000000000002 RSI: 00007fff55d595c0 RDI: 000000000000000b
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000b
R13: 00007f37637e76c8 R14: 0000000000000000 R15: 00007fff55d69786
rcu: rcu_preempt kthread starved for 10559 jiffies! g11189 f0x0 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:27440 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 1
CPU: 1 PID: 4745 Comm: syz.1.100 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0x4ad/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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ee fa 97 f7 48 89 df e8 26 d3 98 f7 e8 91 c5 b9 f7 fb bf 01 00 00 00 a6 d9 8c f7 65 8b 05 47 e7 3c 76 85 c0 74 02 5b c3 e8 94 f4 3a
RSP: 0018:ffffc90003d77bc0 EFLAGS: 00000282
RAX: 3d88d8c095d4a500 RBX: ffff888075b25340 RCX: 3d88d8c095d4a500
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff888075b25343 R09: 1ffff1100eb64a68
R10: dffffc0000000000 R11: ffffed100eb64a69 R12: ffff888075b25340
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
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: 0033:0x7f921187d627
Code: 83 c8 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
RSP: 002b:00007f920fad7028 EFLAGS: 00000246
RAX: 0000000000000048 RBX: 00007f9211af6fa0 RCX: 00007f921187d629
RDX: 0000200000000280 RSI: 0000000000000026 RDI: 0000000000000003
RBP: 00007f9211913b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9211af7038 R14: 00007f9211af6fa0 R15: 00007ffc96174bc8