rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1120/2:b..l rcu: (detected by 0, t=10502 jiffies, g=10745, q=890 ncpus=2) task:kworker/u8:5 state:R running task stack:20888 pid:1120 tgid:1120 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6935 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6959 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:396 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0x1775/0x3f50 net/core/dev.c:4463 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x12c9/0x17b0 net/ipv6/ip6_output.c:141 ip6_finish_output+0x41e/0x840 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xb30/0x1450 net/ipv6/ndisc.c:511 addrconf_dad_completed+0x76c/0xcd0 net/ipv6/addrconf.c:4381 addrconf_dad_work+0xdc2/0x16f0 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 9676 jiffies! g10745 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:25880 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6107 Comm: kworker/1:12 Not tainted 6.13.0-rc6-syzkaller-00036-gfbfd64d25c7a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_long defense_work_handler RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67 Code: e8 95 00 ba 00 48 ba 00 00 00 00 00 fc ff df e9 9f fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 e9 43 59 a4 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 RSP: 0018:ffffc90000a180c8 EFLAGS: 00000087 RAX: ffffc90000a18200 RBX: ffffc90000a18210 RCX: 1ffff92000143040 RDX: ffffffff90a2d566 RSI: 0000000000000002 RDI: ffffc90000a181f8 RBP: ffffc90000a11000 R08: 0000000000000009 R09: ffffc90000a18200 R10: dffffc0000000000 R11: fffff5200014304c R12: ffffc90000a19000 R13: ffffc90000a181f8 R14: ffffc90000a18200 R15: 1ffff92000143042 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ef5ffff CR3: 000000004a324000 CR4: 0000000000350ef0 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0xc9b/0x22d0 arch/x86/kernel/unwind_orc.c:585 __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] dummy_urb_enqueue+0x7d/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1272 usb_hcd_submit_urb+0x36e/0x1e80 drivers/usb/core/hcd.c:1533 ath9k_hif_usb_reg_in_cb+0x4ce/0x6e0 drivers/net/wireless/ath/ath9k/hif_usb.c:790 __usb_hcd_giveback_urb+0x42e/0x6e0 drivers/usb/core/hcd.c:1650 dummy_timer+0x856/0x4620 drivers/usb/gadget/udc/dummy_hcd.c:1993 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59d/0xd30 kernel/time/hrtimer.c:1803 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1820 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:396 Code: 8c e8 24 24 67 0a 65 66 8b 05 f4 00 a2 7e 66 85 c0 75 5d bf 01 00 00 00 e8 5d bd 0b 00 e8 08 69 45 00 fb 65 8b 05 b8 00 a2 7e <85> c0 75 05 e8 37 82 a8 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c RSP: 0018:ffffc90002f17980 EFLAGS: 00000282 RAX: 0000000080000000 RBX: 1ffff920005e2f34 RCX: ffffffff817b378a RDX: dffffc0000000000 RSI: ffffffff8c0a98e0 RDI: ffffffff8c5fb020 RBP: ffffc90002f17a30 R08: ffffffff942a4927 R09: 1ffffffff2854924 R10: dffffc0000000000 R11: fffffbfff2854925 R12: dffffc0000000000 R13: 1ffff920005e2f38 R14: ffffc90002f179c0 R15: 0000000000000200 local_bh_enable include/linux/bottom_half.h:33 [inline] update_defense_level+0x8ec/0xcf0 net/netfilter/ipvs/ip_vs_ctl.c:210 defense_work_handler+0x22/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244