syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (418 ticks this GP) idle=9d7/1/0x4000000000000000 softirq=22263/22263 fqs=24 
	(t=10501 jiffies g=31869 q=345)
rcu: rcu_preempt kthread starved for 9680 jiffies! g31869 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:26168 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7926 Comm: syz-executor Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:cake_dequeue+0x4c6/0x4600 net/sched/sch_cake.c:1985
Code: b6 04 06 84 c0 0f 85 26 02 00 00 45 8b 65 00 31 ff 44 89 e6 e8 5b d9 f7 f8 45 85 e4 4c 89 7c 24 20 78 7c 49 8d bf 2e 98 01 00 <48> 89 f8 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 0f b6 04 10 84
RSP: 0018:ffffc90000006da0 EFLAGS: 00000202
RAX: 0000000000000100 RBX: 00000000018c0001 RCX: ffff8880252f9dc0
RDX: ffff8880252f9dc0 RSI: 0000000000000040 RDI: ffff8880552330fe
RBP: ffffc90000007018 R08: ffffffff8888aee5 R09: fffffbfff2131258
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000040
R13: ffff888055233154 R14: 1ffff1100aa4662a R15: ffff8880552198d0
FS:  00005555784a2500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95514b76e8 CR3: 000000007ed11000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 dequeue_skb net/sched/sch_generic.c:292 [inline]
 qdisc_restart net/sched/sch_generic.c:397 [inline]
 __qdisc_run+0x253/0x1e90 net/sched/sch_generic.c:415
 __dev_xmit_skb net/core/dev.c:3910 [inline]
 __dev_queue_xmit+0xf78/0x32b0 net/core/dev.c:4221
 neigh_hh_output include/net/neighbour.h:493 [inline]
 neigh_output include/net/neighbour.h:507 [inline]
 ip_finish_output2+0xcd7/0x11a0 net/ipv4/ip_output.c:228
 dst_output include/net/dst.h:443 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0x12df/0x1d90 net/ipv4/ip_output.c:532
 sctp_packet_transmit+0x2565/0x2b70 net/sctp/output.c:652
 sctp_outq_flush_transports net/sctp/outqueue.c:1170 [inline]
 sctp_outq_flush+0x13c7/0x3d70 net/sctp/outqueue.c:1218
 sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]
 sctp_do_sm+0x55e7/0x5c80 net/sctp/sm_sideeffect.c:1170
 sctp_generate_heartbeat_event+0x321/0x450 net/sctp/sm_sideeffect.c:391
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:___slab_alloc+0x379/0xe10 mm/slub.c:2982
Code: c7 44 24 40 00 00 00 00 9c 8f 44 24 40 f7 44 24 40 00 02 00 00 0f 85 36 06 00 00 f7 c3 00 02 00 00 74 01 fb 49 83 7c 24 18 00 <0f> 84 c4 00 00 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 4c 8b
RSP: 0018:ffffc90002e1fb90 EFLAGS: 00000282
RAX: a5b4f4718e4c5200 RBX: 0000000000000246 RCX: ffffffff81633db8
RDX: dffffc0000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff2131236
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b8e414e0
R13: 0000000000000000 R14: ffffffff7fff0000 R15: ffff888140007640
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 __d_alloc+0x2a/0x700 fs/dcache.c:1749
 d_alloc+0x48/0x1d0 fs/dcache.c:1828
 lookup_one_qstr_excl+0xca/0x240 fs/namei.c:1559
 filename_create+0x293/0x530 fs/namei.c:3836
 do_mkdirat+0xb3/0x520 fs/namei.c:4080
 __do_sys_mkdir fs/namei.c:4110 [inline]
 __se_sys_mkdir fs/namei.c:4108 [inline]
 __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4108
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f95507cb997
Code: 44 00 00 48 8d 50 ff 83 c1 01 48 21 d0 75 f4 01 cf 48 83 c6 08 4c 39 c6 75 d9 89 f8 c3 31 ff 89 f8 c3 90 b8 53 00 00 00 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:00007fff1d8d1458 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fff1d8d15a2 RCX: 00007f95507cb997
RDX: 000000000cfc7628 RSI: 00000000000001c0 RDI: 00007fff1d8d1590
RBP: f49998db0aa753ff R08: 0000000000000004 R09: 0000000000000001
R10: 00007fff1d9c5080 R11: 0000000000000246 R12: 8421084210842109
R13: 00007fff1d8d15a2 R14: 00007f955084cca0 R15: 000000000cfc7628
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x1b4/0x200 arch/x86/kernel/kvm.c:918
Code: e0 48 c1 e8 03 42 0f b6 04 28 84 c0 75 42 45 0f b6 34 24 e8 0e e0 4e 00 44 3a 74 24 1c 75 10 66 90 0f 00 2d 0e 5e 70 09 fb f4 <e9> c8 fe ff ff fb e9 c2 fe ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 54
RSP: 0018:ffffc90000dd01a0 EFLAGS: 00000246
RAX: 018fea1c0491ac00 RBX: 1ffff920001ba038 RCX: ffffffff81633db8
RDX: dffffc0000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f000
RBP: ffffc90000dd0270 R08: dffffc0000000000 R09: fffffbfff2131239
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88814c87f588
R13: dffffc0000000000 R14: 0000000000000003 R15: ffffc90000dd01e0
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6bc/0xc40 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:363 [inline]
 sctp_rcv+0x1fb8/0x2960 net/sctp/input.c:233
 ip_protocol_deliver_rcu+0x381/0x730 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x1db/0x320 net/ipv4/ip_input.c:231
 NF_HOOK+0x364/0x410 include/linux/netfilter.h:302
 NF_HOOK+0x364/0x410 include/linux/netfilter.h:302
 __netif_receive_skb_one_core net/core/dev.c:5493 [inline]
 __netif_receive_skb+0x1c6/0x530 net/core/dev.c:5607
 process_backlog+0x363/0x7f0 net/core/dev.c:6484
 __napi_poll+0xc7/0x440 net/core/dev.c:7043
 napi_poll net/core/dev.c:7110 [inline]
 net_rx_action+0x617/0xda0 net/core/dev.c:7200
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 do_softirq+0x162/0x240 kernel/softirq.c:459
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:383
 wg_packet_create_data_done drivers/net/wireguard/send.c:247 [inline]
 wg_packet_tx_worker+0x13f/0x7a0 drivers/net/wireguard/send.c:276
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>