rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (2 ticks this GP) idle=2964/1/0x4000000000000000 softirq=18754/18754 fqs=0
rcu: (detected by 0, t=10502 jiffies, g=13505, q=303 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1093 Comm: kworker/u8:5 Not tainted 6.16.0-rc7-syzkaller-00091-geccf7a3480a0 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x44/0x3e0 kernel/locking/lockdep.c:5882
Code: 8b 05 90 84 01 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 93 84 01 11 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 3c 93 03 0e <73> 16 e8 d5 df 08 00 84 c0 75 0d f6 05 e7 75 ed 0d 01 0f 84 ad 02
RSP: 0018:ffffc90000a07f28 EFLAGS: 00000097
RAX: 0000000000000001 RBX: ffffffff898d7218 RCX: ffff888026a93c00
RDX: 0000000000010100 RSI: ffffffff898d7218 RDI: ffffffff8e13f0e0
RBP: 0000000000000001 R08: ffff88807d23e15f R09: 1ffff1100fa47c2b
R10: dffffc0000000000 R11: ffffed100fa47c2c R12: ffff88807d23e360
R13: ffffffff898d7218 R14: ffffffff8e13f0e0 R15: ffff888057dd9c00
FS: 0000000000000000(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000007479c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:987
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:unwind_next_frame+0x1822/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 74 05 e8 7d 76 af 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03 <80> 3c 28 00 74 05 e8 63 76 af 00 4d 8b 6e 08 4d 8d 7e 10 4c 89 f8
RSP: 0018:ffffc90000a083d8 EFLAGS: 00000a06
RAX: 1ffff92000141096 RBX: ffffffff903dcc01 RCX: 0000000000000001
RDX: ffffc90000a084e8 RSI: dffffc0000000000 RDI: ffffc90000a084b0
RBP: dffffc0000000000 R08: ffffc90000a08890 R09: 0000000000000000
R10: ffffc90000a084f8 R11: fffff520001410a1 R12: ffffc90000a088a0
R13: ffffc90000a084f8 R14: ffffc90000a084a8 R15: ffffffff8172aae5
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:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4643 [inline]
kmem_cache_free+0x18f/0x400 mm/slub.c:4745
kfree_skb_reason include/linux/skbuff.h:1275 [inline]
kfree_skb include/linux/skbuff.h:1284 [inline]
ip6_mc_input+0x9c3/0xbe0 net/ipv6/ip6_input.c:591
NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:317
__netif_receive_skb_one_core net/core/dev.c:5977 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6090
process_backlog+0x60e/0x14f0 net/core/dev.c:6442
__napi_poll+0xc4/0x480 net/core/dev.c:7414
napi_poll net/core/dev.c:7478 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7605
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
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
__dev_queue_xmit+0x1cd7/0x3a70 net/core/dev.c:4740
dev_queue_xmit include/linux/netdevice.h:3355 [inline]
neigh_hh_output include/net/neighbour.h:523 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip6_finish_output2+0x11bc/0x16a0 net/ipv6/ip6_output.c:141
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:317
mld_sendpack+0x800/0xd80 net/ipv6/mcast.c:1868
ipv6_mc_dad_complete+0x88/0x4b0 net/ipv6/mcast.c:2293
addrconf_dad_completed+0x6d5/0xd60 net/ipv6/addrconf.c:4339
addrconf_dad_work+0xc36/0x14b0 net/ipv6/addrconf.c:-1
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13505 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=6322
rcu: rcu_preempt kthread starved for 10502 jiffies! g13505 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245