rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=87ac/1/0x4000000000000000 softirq=8592/8592 fqs=302 rcu: (detected by 0, t=10502 jiffies, g=10597, q=1699 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted 6.7.0-rc3-syzkaller-00118-g79321a793945 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5730 [inline] RIP: 0010:lock_acquire+0x110/0x520 kernel/locking/lockdep.c:5719 Code: 11 38 d0 7c 08 84 d2 0f 85 be 03 00 00 8b 0d 7f 51 b1 0d 85 c9 0f 84 e4 00 00 00 65 8b 05 80 6d 9a 7e 85 c0 0f 85 1a 01 00 00 <65> 48 8b 14 25 c0 bc 03 00 48 8d ba bc 0a 00 00 48 b8 00 00 00 00 RSP: 0018:ffffc900001f0ca0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff9200003e196 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b2f0e00 RDI: ffffffff8ca73a68 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff1e3273a R10: ffffffff8f1939d7 R11: 0000000000000005 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8cfabbe0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f53185fb3b0 CR3: 0000000017b1e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] advance_sched+0x67c/0xc60 net/sched/sch_taprio.c:996 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x203/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:fib6_clean_node+0xd9/0x5b0 net/ipv6/ip6_fib.c:2177 Code: 48 49 8d 7c 24 68 48 89 fa 48 c1 ea 03 48 89 44 24 48 48 b8 00 00 00 00 00 fc ff df 0f b6 04 02 84 c0 74 06 0f 8e 07 04 00 00 <0f> b6 44 24 54 49 8d 7c 24 58 41 0f b6 54 24 68 88 04 24 83 e0 fe RSP: 0018:ffffc90000a2f810 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff8937ac1d RDX: 1ffff92000145f44 RSI: ffffffff8938c52a RDI: ffffc90000a2fa20 RBP: ffffc90000a2f9b8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000005 R12: ffffc90000a2f9b8 R13: 1ffff92000145f3c R14: 0000000000000000 R15: 0000000000000000 fib6_walk_continue+0x44c/0x8c0 net/ipv6/ip6_fib.c:2118 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2166 fib6_clean_tree+0xd7/0x110 net/ipv6/ip6_fib.c:2246 __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2262 rt_genid_bump_ipv6 include/net/net_namespace.h:523 [inline] addrconf_dad_completed+0x87d/0x1030 net/ipv6/addrconf.c:4317 addrconf_dad_work+0x7f6/0x14b0 net/ipv6/addrconf.c:4211 process_one_work+0x886/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 9896 jiffies! g10597 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:28752 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xedb/0x5af0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6778 schedule_timeout+0x137/0x290 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.7.0-rc3-syzkaller-00118-g79321a793945 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__sanitizer_cov_trace_pc+0x59/0x60 kernel/kcov.c:225 Code: 82 d8 15 00 00 83 f8 02 75 20 48 8b 8a e0 15 00 00 8b 92 dc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 66 0f 1f 44 00 00 f3 0f 1e fa 41 57 41 56 49 89 d6 41 55 41 54 RSP: 0018:ffffc90000107928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9941a60 RCX: ffffffff817bd1e8 RDX: ffff888017e4bb80 RSI: ffffffff817bd1c2 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed101732834d R13: 0000000000000001 R14: ffff8880b9941a68 R15: ffff8880b983d8c0 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f53185c7ba8 CR3: 000000000cd77000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:311 [inline] smp_call_function_many_cond+0x4e2/0x1550 kernel/smp.c:855 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2006 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2216 text_poke_flush arch/x86/kernel/alternative.c:2407 [inline] text_poke_flush arch/x86/kernel/alternative.c:2404 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2414 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:830 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822 process_one_work+0x886/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242