rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=58849, q=538426 ncpus=2)
task:kworker/1:0 state:R running task stack:20784 pid:24 tgid:24 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 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 00 02 00 00 74 01 fb 65 48 8b 05 4b 80 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900001e6e98 EFLAGS: 00000206
RAX: 2ac4b0e11ea68600 RBX: 0000000000000000 RCX: 2ac4b0e11ea68600
RDX: 0000000000000000 RSI: ffffffff8dba9b22 RDI: ffffffff8be33f80
RBP: ffffffff8172c195 R08: 0000000000000000 R09: ffffffff8172c195
R10: dffffc0000000000 R11: ffffffff81ac3c30 R12: 0000000000000002
R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
discard_slab mm/slub.c:2758 [inline]
__put_partials+0x156/0x1a0 mm/slub.c:3223
put_cpu_partial+0x17c/0x250 mm/slub.c:3298
__slab_free+0x2d5/0x3c0 mm/slub.c:4565
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
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]
__do_kmalloc_node mm/slub.c:4375 [inline]
__kmalloc_noprof+0x224/0x4f0 mm/slub.c:4388
kmalloc_noprof include/linux/slab.h:909 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
rh_call_control drivers/usb/core/hcd.c:491 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:821 [inline]
usb_hcd_submit_urb+0x798/0x1aa0 drivers/usb/core/hcd.c:1542
usb_start_wait_urb+0x114/0x4c0 drivers/usb/core/message.c:59
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154
usb_clear_port_feature drivers/usb/core/hub.c:460 [inline]
port_event drivers/usb/core/hub.c:5764 [inline]
hub_event+0x834/0x4a20 drivers/usb/core/hub.c:5952
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 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 280 jiffies! g58849 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:26192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:timer_delete_sync+0x0/0x20 kernel/time/timer.c:1674
Code: ff 4c 89 e7 e8 11 1a 76 00 e9 5a ff ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 53 48 89 fb e8 f3 9b 12 00 48 89 df 31 f6 5b eb 1b 66
RSP: 0018:ffffc90000157a58 EFLAGS: 00000246
RAX: 0000000000208040 RBX: 000000010001376c RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8be33f60 RDI: ffffc90000157a80
RBP: ffffc90000157b50 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 1ffff9200002af4c
R13: 1ffffffff1bc2240 R14: ffffc90000157a80 R15: dffffc0000000000
schedule_timeout+0x133/0x270 kernel/time/sleep_timeout.c:100
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+0x439/0x7d0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3418 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:arch_stack_walk+0x123/0x150 arch/x86/kernel/stacktrace.c:24
Code: 25 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 2e e8 f0 b6 13 0a 84 c0 74 11 4c 89 ff e8 94 26 09 00 83 bd 78 ff ff ff 00 <75> cf 65 48 8b 05 b3 45 37 11 48 3b 45 d8 75 12 48 83 c4 68 5b 41
RSP: 0018:ffffc90000006908 EFLAGS: 00000202
RAX: 0000000090bf1a01 RBX: ffffc900000069c0 RCX: 7b9eb298d8874500
RDX: 0000000000000005 RSI: ffffffff8dba9b22 RDI: ffff888030389e00
RBP: ffffc90000006990 R08: ffffc90000007850 R09: ffffc90000006958
R10: dffffc0000000000 R11: fffff52000000d2d R12: ffff888030389e00
R13: ffff88807b124f00 R14: ffffffff81ac3c30 R15: ffffc90000006908
FS: 0000000000000000(0000) GS:ffff888125c12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdd0a40f80 CR3: 0000000027def000 CR4: 0000000000350ef0
Call Trace:
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 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+0x1c1/0x3c0 mm/slub.c:4247
dst_alloc+0x105/0x170 net/core/dst.c:89
rt_dst_alloc net/ipv4/route.c:1645 [inline]
__mkroute_output net/ipv4/route.c:2649 [inline]
ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2870
ip_route_output_key_hash+0x1b9/0x2e0 net/ipv4/route.c:2700
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x6d2/0x1030 net/ipv4/netfilter.c:53
synproxy_send_tcp+0x359/0x6c0 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:5991 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6104
process_backlog+0x60e/0x14f0 net/core/dev.c:6456
__napi_poll+0xc7/0x360 net/core/dev.c:7506
napi_poll net/core/dev.c:7569 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7696
handle_softirqs+0x286/0x870 kernel/softirq.c:579
do_softirq+0xec/0x180 kernel/softirq.c:480
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1315
batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3509
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3496
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245