rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l P66/2:b..l
rcu: (detected by 0, t=10503 jiffies, g=9793, q=432 ncpus=2)
task:kworker/u4:4 state:R running task stack:24336 pid:66 ppid:2 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__local_bh_enable_ip+0x13f/0x1c0 kernel/softirq.c:413
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:856 [inline]
__dev_queue_xmit+0x1449/0x35a0 net/core/dev.c:4452
neigh_output include/net/neighbour.h:543 [inline]
ip6_finish_output2+0xe2e/0x1650 net/ipv6/ip6_output.c:141
dst_output include/net/dst.h:467 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513
addrconf_dad_completed+0x79f/0xd40 net/ipv6/addrconf.c:4324
addrconf_dad_work+0xc4e/0x14e0 net/ipv6/addrconf.c:-1
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
task:kworker/u4:1 state:R running task stack:24616 pid:12 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc90000117a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 405c8b7625b18800
RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6f80
RBP: ffffc90000117b48 R08: dffffc0000000000 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: 1ffff92000022f54
R13: ffffffff8cd2ff20 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: rcu_preempt kthread starved for 10558 jiffies! g9793 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:26568 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 66 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 6a d7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 d3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 89 d3
RSP: 0018:ffffc900015e7780 EFLAGS: 00000293
RAX: ffffffff817abd37 RBX: 1ffff110171c8759 RCX: ffff88801eadbc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900015e7900 R08: ffffffff90d94507 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: ffff8880b8e43ac8
R13: dffffc0000000000 R14: ffff8880b8f3d148 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293