rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=193529, q=190 ncpus=1)
task:kthreadd state:R running task stack:26888 pid:2 tgid:2 ppid:0 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x45/0x2f0 kernel/locking/lockdep.c:5879
Code: b9 e3 08 12 48 89 44 24 10 31 c0 0f 1f 44 00 00 65 8b 05 d2 e3 08 12 83 f8 07 0f 87 38 02 00 00 89 c0 48 0f a3 05 5b fe e9 0e <0f> 82 b1 01 00 00 8b 3d b3 2e ea 0e 85 ff 0f 84 25 01 00 00 65 8b
RSP: 0018:ffffc90000077598 EFLAGS: 00000297
RAX: 0000000000000000 RBX: ffffffff8e3c45e0 RCX: ffffc90000078001
RDX: 0000000000000000 RSI: ffffffff816bb704 RDI: ffffffff8e3c45e0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000085c6 R12: ffffffff816bb704
R13: ffffc90000077650 R14: ffffc90000077f18 R15: ffffc90000077684
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3f9/0x20a0 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
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5295
alloc_pid+0xc7/0xbc0 kernel/pid.c:184
copy_process+0x49a3/0x76a0 kernel/fork.c:2197
kernel_clone+0xfc/0x930 kernel/fork.c:2609
kernel_thread+0xd7/0x120 kernel/fork.c:2670
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x503/0x800 kernel/kthread.c:846
ret_from_fork+0x675/0x7d0 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 355 jiffies! g193529 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:28552 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 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: 3411 Comm: kworker/R-bat_e Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 38 24 09 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 4d e2 08 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc900000063d8 EFLAGS: 00000206
RAX: edaf9a2e64f5aa00 RBX: ffffffff8e3c45e0 RCX: ffffc900000063e4
RDX: 0000000000000007 RSI: ffffffff8da037dc RDI: ffffffff8bf078c0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000092c67 R12: ffffffff816bb704
R13: 0000000000000206 R14: ffff888030d18000 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557351f510 CR3: 00000000223a8000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3f9/0x20a0 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:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2543 [inline]
slab_free mm/slub.c:6642 [inline]
kmem_cache_free+0x2d4/0x6c0 mm/slub.c:6752
__skb_ext_put+0x102/0x2c0 net/core/skbuff.c:7160
skb_ext_reset include/linux/skbuff.h:4999 [inline]
skb_scrub_packet+0x372/0x430 net/core/skbuff.c:6180
____dev_forward_skb include/linux/netdevice.h:4330 [inline]
__dev_forward_skb2+0x379/0x750 net/core/dev.c:2420
veth_forward_skb drivers/net/veth.c:319 [inline]
veth_xmit+0x2bd/0xe90 drivers/net/veth.c:375
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3861
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4763
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
br_dev_queue_push_xmit+0x272/0x8a0 net/bridge/br_forward.c:53
br_nf_dev_queue_xmit+0x6e0/0x2b20 net/bridge/br_netfilter_hooks.c:920
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_nf_post_routing+0x8e7/0x1190 net/bridge/br_netfilter_hooks.c:966
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook+0x45e/0x780 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
br_forward_finish+0xcd/0x130 net/bridge/br_forward.c:66
br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167
br_nf_forward_finish+0x66a/0xba0 net/bridge/br_netfilter_hooks.c:662
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_nf_forward_ip.part.0+0x609/0x810 net/bridge/br_netfilter_hooks.c:716
br_nf_forward_ip net/bridge/br_netfilter_hooks.c:676 [inline]
br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:773
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook+0x45e/0x780 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
__br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xf1/0x180 net/bridge/br_forward.c:191
br_flood+0x17c/0x650 net/bridge/br_forward.c:238
br_handle_frame_finish+0x1117/0x1f00 net/bridge/br_input.c:229
br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167
br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 net/bridge/br_netfilter_ipv6.c:154
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184
br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0xb28/0x14e0 net/bridge/br_input.c:442
__netif_receive_skb_core.constprop.0+0xa25/0x4bd0 net/core/dev.c:5966
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6077
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
process_backlog+0x439/0x15e0 net/core/dev.c:6544
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x97f/0xef0 net/core/dev.c:7784
handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:510
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__batadv_dat_purge.part.0+0x279/0x3a0 net/batman-adv/distributed-arp-table.c:185
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:166 [inline]
batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:204
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
rescuer_thread+0x620/0xea0 kernel/workqueue.c:3523
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245