rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=38733, q=1706067 ncpus=2)
task:kworker/1:1 state:R running task stack:22016 pid:29 tgid:29 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7235
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x9/0x3d0 kernel/locking/lockdep.c:5876
Code: ff 41 be 2f 00 00 00 e9 0e ff ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 <41> 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 20 18 7a
RSP: 0018:ffffc90000a56338 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90000a56401 RCX: 0000000080000001
RDX: ffffffff90b3d501 RSI: ffffffff81767de5 RDI: ffffffff8e75e420
RBP: dffffc0000000000 R08: ffffc90000a56487 R09: ffffc90000a56478
R10: dffffc0000000000 R11: fffff5200014ac91 R12: ffffc90000a56858
R13: ffffc90000a50000 R14: ffffc90000a56428 R15: ffffffff81767de5
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
__slab_free+0x263/0x2b0 mm/slub.c:5576
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4542 [inline]
slab_alloc_node mm/slub.c:4869 [inline]
__do_kmalloc_node mm/slub.c:5262 [inline]
__kmalloc_noprof+0x316/0x760 mm/slub.c:5275
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
kobject_get_path+0xc5/0x2f0 lib/kobject.c:161
kobject_uevent_env+0x2a1/0x9e0 lib/kobject_uevent.c:545
device_del+0x750/0x8f0 drivers/base/core.c:3896
snd_card_disconnect+0x4b7/0x870 sound/core/init.c:546
snd_card_free_when_closed sound/core/init.c:617 [inline]
snd_card_free+0x129/0x1d0 sound/core/init.c:650
usb_audio_probe+0x1da8/0x2330 sound/usb/card.c:1080
usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x279/0x430 drivers/base/dd.c:961
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c5/0x450 drivers/base/dd.c:1033
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb70 drivers/base/core.c:3689
usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2208
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x279/0x430 drivers/base/dd.c:961
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c5/0x450 drivers/base/dd.c:1033
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb70 drivers/base/core.c:3689
usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 2701 jiffies! g38733 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:27648 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
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+0x51e/0xb90 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3403 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:unwind_next_frame+0x77/0x23c0 arch/x86/kernel/unwind_orc.c:487
Code: 4c 89 e8 48 c1 e8 03 48 89 44 24 58 80 3c 28 00 74 08 4c 89 ef e8 c9 5a b9 00 4d 8b 7e 38 4d 89 f4 49 c1 ec 03 41 0f b6 04 2c <84> c0 0f 85 e7 1b 00 00 41 8b 06 85 c0 0f 84 4f 02 00 00 89 84 24
RSP: 0018:ffffc90000a07eb8 EFLAGS: 00000212
RAX: 0000000000000000 RBX: ffffffff816d0ec3 RCX: 0000000080000101
RDX: ffffc90000a08078 RSI: dffffc0000000000 RDI: ffffc90000a07fe8
RBP: dffffc0000000000 R08: ffffc90000a07fd8 R09: ffffc90000a08038
R10: dffffc0000000000 R11: fffff52000141009 R12: 1ffff92000140ffd
R13: ffffc90000a08020 R14: ffffc90000a07fe8 R15: ffffc90000a07fe8
FS: 0000000000000000(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 000000005b12f000 CR4: 0000000000350ef0
Call Trace:
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
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:2692 [inline]
slab_free mm/slub.c:6168 [inline]
kmem_cache_free+0x187/0x630 mm/slub.c:6298
nft_synproxy_eval_v4+0x352/0x4e0 net/netfilter/nft_synproxy.c:61
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+0x45e/0x1990 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x29d/0x380 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+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:6164 [inline]
__netif_receive_skb net/core/dev.c:6277 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6628
__napi_poll+0xae/0x340 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7912
handle_softirqs+0x22a/0x870 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:395 [inline]
batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline]
batadv_tt_purge+0x4d1/0x9e0 net/batman-adv/translation-table.c:3510
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
rescuer_thread+0x824/0x1120 kernel/workqueue.c:3582
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245