rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21538/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=137017, q=1846258 ncpus=2)
task:kworker/0:8 state:R running task stack:24488 pid:21538 tgid:21538 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 f8 2d 3f 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 0d ec 3e 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0000:ffffc900065a7b10 EFLAGS: 00000206
RAX: a48a3a4e0837e700 RBX: ffffffff8e5c1260 RCX: ffffc900065a7b1c
RDX: 0000000000000002 RSI: ffffffff8de2cdc0 RDI: ffffffff8c162d80
RBP: ffffffff9b2cb2ac R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff89ba90d9
R13: 0000000000000202 R14: ffff888055f68000 R15: 0000000000000003
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
gc_worker+0x99e/0x16e0 net/netfilter/nf_conntrack_core.c:1617
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10523 jiffies! g137017 f0x2 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:27368 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3422 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_tt_purge
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline]
RIP: 0010:__rcu_read_lock+0x2a/0xf0 kernel/rcu/tree_plugin.h:414
Code: f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 65 48 8b 1d 90 10 36 12 48 8d bb 44 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a6 00 00 00 65
RSP: 0018:ffffc90000a07cc0 EFLAGS: 00000a03
RAX: dffffc0000000000 RBX: ffff8880325ac880 RCX: ffffc90000a07c9c
RDX: 0000000000000000 RSI: ffffffff89f826f5 RDI: ffff8880325accc4
RBP: ffffc90000a07d90 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000087300 R12: ffffffff81a6ddc0
R13: ffffc90000a07d48 R14: 0000000000000000 R15: ffff8880325ac880
FS: 0000000000000000(0000) GS:ffff8881247b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000dde000 CR3: 000000004275c000 CR4: 00000000003526f0
DR0: 0000040000000000 DR1: 0000000000000001 DR2: 0000000000000008
DR3: 0000000000000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
dst_alloc+0x99/0x1a0 net/core/dst.c:89
rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1645
__mkroute_output net/ipv4/route.c:2649 [inline]
ip_route_output_key_hash_rcu+0x87a/0x28e0 net/ipv4/route.c:2870
ip_route_output_key_hash+0x137/0x2e0 net/ipv4/route.c:2700
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2927
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x55d/0x12e0 net/ipv4/netfilter.c:53
synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431
synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623
nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:260
dst_input include/net/dst.h:471 [inline]
ip_rcv_finish net/ipv4/ip_input.c:454 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5991
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6104
process_backlog+0x442/0x15e0 net/core/dev.c:6456
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7506
napi_poll net/core/dev.c:7569 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696
handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
do_softirq kernel/softirq.c:480 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:467
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_tt_local_purge+0x21c/0x3c0 net/batman-adv/translation-table.c:1315
batadv_tt_purge+0x8b/0xb80 net/batman-adv/translation-table.c:3509
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
rescuer_thread+0x620/0xea0 kernel/workqueue.c:3496
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245