rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31056/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=269505, q=2301 ncpus=2)
task:udevd state:R running task stack:26808 pid:31056 tgid:31056 ppid:4996 task_flags:0x40014c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
RIP: 0010:unwind_next_frame+0xdec/0x2550 arch/x86/kernel/unwind_orc.c:614
Code: 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f 85 2c 12 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 c1 <49> 39 dc 0f 97 c0 20 c8 3c 01 75 18 48 8d 43 08 4c 39 f8 0f 97 c1
RSP: 0018:ffffc9000e7df358 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000e7df518 RCX: 1ffff92001cfbe01
RDX: ffffffff90c3f8a4 RSI: 0000000000000002 RDI: ffffffff8c28ac00
RBP: 1ffff92001cfbe92 R08: 0000000000000007 R09: ffffffff8e95cd60
R10: ffffc9000e7df4d8 R11: fffff52001cfbe9d R12: ffffc9000e7e0000
R13: 1ffff92001cfbe93 R14: ffffc9000e7df488 R15: ffffc9000e7d8000
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6246 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6373
anon_vma_chain_free mm/rmap.c:147 [inline]
unlink_anon_vmas+0x69d/0x730 mm/rmap.c:539
free_pgtables+0x836/0xb70 mm/memory.c:414
exit_mmap+0x490/0x9e0 mm/mmap.c:1312
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
__do_sys_exit_group kernel/exit.c:1128 [inline]
__se_sys_exit_group kernel/exit.c:1126 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1126
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6505cf16c5
RSP: 002b:00007ffd960c69e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055bbb987d050 RCX: 00007f6505cf16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055bbb9854910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd960c6a30 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 370 jiffies! g269505 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:26880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
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: 21691 Comm: kworker/0:5 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline]
RIP: 0010:read_seqbegin include/linux/seqlock.h:838 [inline]
RIP: 0010:neigh_hh_output include/net/neighbour.h:510 [inline]
RIP: 0010:neigh_output include/net/neighbour.h:554 [inline]
RIP: 0010:ip_finish_output2+0x930/0x1070 net/ipv4/ip_output.c:237
Code: 16 1d b6 f7 4d 85 f6 75 16 e8 0c 1d b6 f7 eb 15 e8 05 1d b6 f7 e8 00 a6 98 01 4d 85 f6 74 ea e8 f6 1c b6 f7 fb 48 8b 44 24 38 <42> 0f b6 04 38 84 c0 0f 85 92 01 00 00 48 8b 04 24 44 8b 30 44 89
RSP: 0018:ffffc900000071c0 EFLAGS: 00000246
RAX: 1ffff1100d852e3d RBX: 0000000000000000 RCX: ffff888041fe8000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88806c2971f0 R08: ffffffff9030a6f7 R09: 1ffffffff20614de
R10: dffffc0000000000 R11: fffffbfff20614df R12: ffff8881a1fc5850
R13: ffff8881a1fc5858 R14: 0000000000000200 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125290000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3a2439 CR3: 00000000666fa000 CR4: 00000000003526f0
Call Trace:
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
synproxy_send_client_synack+0x8c1/0xe30 net/netfilter/nf_synproxy_core.c:485
nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x467/0x19f0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7950
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
neigh_periodic_work+0xc28/0xe50 net/core/neighbour.c:1038
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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