rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3458/2:b..l P6134/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=11901, q=565 ncpus=2)
task:dhcpcd state:R running task stack:24088 pid:6134 tgid:6134 ppid:5493 task_flags:0x40014c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__rcu_read_lock+0x30/0x60 kernel/rcu/tree_plugin.h:416
Code: 48 8b 1c 25 08 40 c4 92 48 81 c3 84 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 <8b> 03 3d 00 00 00 40 7d 07 5b e9 41 9b c1 09 cc 90 0f 0b 90 eb f3
RSP: 0018:ffffc90002ea7388 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff888025ef0484 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff81000130 RDI: ffffc90002ea7468
RBP: dffffc0000000000 R08: ffffc90002ea7530 R09: 000000000000000e
R10: ffffc90002ea74b8 R11: ffffffff81addd50 R12: 1ffff920005d4e8d
R13: ffffc90002ea74a0 R14: ffffc90002ea7468 R15: ffffc90002ea7f48
rcu_read_lock include/linux/rcupdate.h:865 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x9e/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
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:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6785
anon_vma_chain_free mm/rmap.c:146 [inline]
unlink_anon_vmas+0x614/0x670 mm/rmap.c:446
free_pgtables+0x737/0x9d0 mm/memory.c:414
exit_mmap+0x431/0xb10 mm/mmap.c:1288
__mmput+0x118/0x430 kernel/fork.c:1177
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x850/0x25b0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f586e2d16c5
RSP: 002b:00007fffbd070268 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f586e2d16c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 00007fffbd070878 R08: 0000563bcfff62c0 R09: 0000000000000002
R10: 00000000000000e0 R11: 0000000000000206 R12: 00007fffbd0702b0
R13: 0000563bcfff78a0 R14: 00007fffbd0704f0 R15: 00007fffbd0702a0
task:kworker/u8:10 state:R running task stack:23824 pid:3458 tgid:3458 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:457
spin_unlock_bh include/linux/spinlock.h:396 [inline]
neigh_forced_gc net/core/neighbour.c:295 [inline]
neigh_alloc net/core/neighbour.c:513 [inline]
___neigh_create+0x5fc/0x2240 net/core/neighbour.c:656
ip6_finish_output2+0x1175/0x1480 net/ipv6/ip6_output.c:128
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xbce/0x1510 net/ipv6/ndisc.c:512
ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:670
addrconf_dad_work+0xaae/0x14b0 net/ipv6/addrconf.c:4282
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
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: rcu_preempt kthread starved for 10572 jiffies! g11901 f0x0 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:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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:
CPU: 1 UID: 0 PID: 6146 Comm: syz.3.46 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a fe 34 f6 48 89 df e8 52 75 35 f6 e8 4d f3 5f f6 fb bf 01 00 00 00 82 6a 27 f6 65 8b 05 db 5f 5a 07 85 c0 74 07 5b e9 c1 4b 00 00
RSP: 0018:ffffc90003bb7c60 EFLAGS: 00000286
RAX: 386ec6292cb06600 RBX: ffff888029c80000 RCX: 386ec6292cb06600
RDX: 0000000000000000 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: 0000000000000011 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: 1ffff11005390053
R13: 0000000000000000 R14: 0000000004000000 R15: ffff888029c80298
FS: 00007f24a1bfe6c0(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffde54f9dd8 CR3: 0000000077b9a000 CR4: 00000000003526f0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11a7/0x1340 kernel/signal.c:3037
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f24a258f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f24a1bfe0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f24a27e5fa8 RCX: 00007f24a258f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f24a27e5fa8
RBP: 00007f24a27e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f24a27e6038 R14: 00007ffd0c9413b0 R15: 00007ffd0c941498