rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=99729, q=237503 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295094026-4295083523), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g99729 f0x2 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:27104 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18216 Comm: syz.7.3474 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_acquire+0x147/0x340 kernel/locking/lockdep.c:5871
Code: c7 20 a7 97 8d e8 19 a0 bd 09 b8 ff ff ff ff 65 0f c1 05 3c b6 e0 10 83 f8 01 0f 85 c9 00 00 00 48 c7 44 24 30 00 00 00 00 9c <8f> 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08
RSP: 0018:ffffc900000067d0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: f9934c708a535200
RDX: 000000007f45ee1d RSI: ffffffff8d97a720 RDI: ffffffff8bc08360
RBP: ffffffff81743f85 R08: ffffffff81743f85 R09: ffffffff8df41a60
R10: ffffc90000006998 R11: ffffffff81ada980 R12: 0000000000000002
R13: ffffffff8df41a60 R14: 0000000000000000 R15: 0000000000000246
FS: 00007f5ca0bf66c0(0000) GS:ffff888125e31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c96400000 CR3: 000000007ed20000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_netdev_trace_buffer+0xd7/0x5a0 net/core/dev.c:13435
__dev_hold include/linux/netdevice.h:4400 [inline]
netdev_hold include/linux/netdevice.h:4443 [inline]
dst_init+0x6f/0x460 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:93
rt_dst_alloc net/ipv4/route.c:1651 [inline]
__mkroute_output net/ipv4/route.c:2655 [inline]
ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2875
ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2705
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2932
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x6c4/0xf10 net/ipv4/netfilter.c:53
synproxy_send_tcp+0x3a7/0x700 net/netfilter/nf_synproxy_core.c:431
synproxy_send_client_synack+0x8bb/0xe20 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6138 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6251
process_backlog+0x622/0x1500 net/core/dev.c:6603
__napi_poll+0xae/0x320 net/core/dev.c:7667
napi_poll net/core/dev.c:7730 [inline]
net_rx_action+0x672/0xe50 net/core/dev.c:7882
handle_softirqs+0x27d/0x850 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count_add+0x0/0x190 kernel/sched/core.c:5714
Code: c1 7c 97 48 8b 3c 24 e8 be 05 97 00 eb 8c e9 f1 fe ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0
RSP: 0018:ffffc9000b48eae0 EFLAGS: 00000246
RAX: ffffffff81fef2d3 RBX: 1ffff92001691e72 RCX: 0000000000080000
RDX: ffffc9000e8e3000 RSI: 000000000007ffff RDI: 0000000000000001
RBP: ffffc9000b48eeb0 R08: ffffc9000b48ed0f R09: 0000000000000000
R10: ffffc9000b48ecd0 R11: fffff52001691da2 R12: ffffc9000b48ecd0
R13: dffffc0000000000 R14: ffffc9000b48f390 R15: 0000000000000030
lru_add_drain+0x1d/0x3e0 mm/swap.c:736
lru_gen_shrink_lruvec mm/vmscan.c:5017 [inline]
shrink_lruvec+0x215/0x2980 mm/vmscan.c:5784
shrink_node_memcgs mm/vmscan.c:6020 [inline]
shrink_node+0xaa9/0x35b0 mm/vmscan.c:6061
shrink_zones mm/vmscan.c:6300 [inline]
do_try_to_free_pages+0x668/0x1960 mm/vmscan.c:6362
try_to_free_mem_cgroup_pages+0x2ea/0x7a0 mm/vmscan.c:6690
try_charge_memcg+0xa2d/0x1280 mm/memcontrol.c:2388
try_charge mm/memcontrol.c:2530 [inline]
charge_memcg+0x9f/0x180 mm/memcontrol.c:4728
mem_cgroup_swapin_charge_folio+0x262/0x390 mm/memcontrol.c:4814
__read_swap_cache_async+0x212/0x480 mm/swap_state.c:481
swap_cluster_readahead+0x500/0x630 mm/swap_state.c:665
shmem_swapin_cluster mm/shmem.c:1745 [inline]
shmem_swapin_folio+0xe47/0x22e0 mm/shmem.c:2329
shmem_get_folio_gfp+0x38a/0x1660 mm/shmem.c:2489
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3315
generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3490
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c9fd8e1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f5ca0bf5df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007f5c9fd8e1ff
RDX: 00000000013bd7ef RSI: 00007f5c95a00000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000054ff
R10: 0000200000002482 R11: 0000000000000293 R12: 0000000000000006
R13: 00007f5ca0bf5ef0 R14: 00007f5ca0bf5eb0 R15: 00007f5c95a00000