INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=2245, c=2244, q=481) All QSes seen, last rcu_preempt kthread activity 10488 (4294968563-4294958075), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 28240 8391 6358 0x00000008 Call Trace: sched_show_task kernel/sched/core.c:5168 [inline] sched_show_task.cold+0x335/0x399 kernel/sched/core.c:5143 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline] check_cpu_stall kernel/rcu/tree.c:1616 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0xd3f/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle.isra.0+0x73/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x41/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x24b/0xb90 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5f0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:unwind_next_frame+0x6eb/0x1700 arch/x86/kernel/unwind_orc.c:420 RSP: 0018:ffff8880aed071a8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000001 RBX: 1ffff11015da0e3c RCX: ffffffff8918cc38 RDX: ffff8880aed07870 RSI: ffff8880aed07160 RDI: ffff8880aed07868 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001 R10: 00000000000dedfe R11: 0000000000056071 R12: ffff8880aed0728d R13: ffff8880aed07290 R14: ffff8880aed072a8 R15: ffff8880aed07258 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552 kmem_cache_zalloc include/linux/slab.h:651 [inline] fill_pool lib/debugobjects.c:110 [inline] __debug_object_init+0x57d/0x7a0 lib/debugobjects.c:341 debug_object_init lib/debugobjects.c:393 [inline] debug_object_activate+0x274/0x450 lib/debugobjects.c:474 debug_rcu_head_queue kernel/rcu/rcu.h:152 [inline] __call_rcu.constprop.0+0x31/0x7e0 kernel/rcu/tree.c:3050 dst_release+0x56/0x80 net/core/dst.c:188 refdst_drop include/net/dst.h:286 [inline] skb_dst_drop include/net/dst.h:298 [inline] __dev_queue_xmit+0x16ed/0x25a0 net/core/dev.c:3484 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip6_finish_output2+0xdab/0x21b0 net/ipv6/ip6_output.c:120 ip6_finish_output+0x702/0xaf0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip6_output+0x1c5/0x660 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:462 [inline] NF_HOOK include/linux/netfilter.h:250 [inline] ndisc_send_skb+0x88b/0x1390 net/ipv6/ndisc.c:483 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677 addrconf_rs_timer+0x280/0x5a0 net/ipv6/addrconf.c:3765 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers+0x233/0x4d0 kernel/time/timer.c:1318 __run_timers kernel/time/timer.c:1636 [inline] run_timer_softirq+0x1d8/0x5b0 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5f0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:preempt_schedule_irq+0xa6/0x140 kernel/sched/core.c:3611 RSP: 0018:ffff88804ef57750 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0f62c9b RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88804ec8eec8 RDI: ffff88804ec8eec4 RBP: ffffed1009d91cc8 R08: ffff88821fff705c R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804ec8e640 R13: ffffffff87b164d8 R14: 0000000000000000 R15: 0000000000000000 retint_kernel+0x1b/0x2d RIP: 0010:number+0x49/0x910 lib/vsprintf.c:402 RSP: 0018:ffff88804ef57820 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: ffffed1009deaf0e RBX: dffffc0000000000 RCX: ffff0a01ffffff10 RDX: 00000000000020c2 RSI: ffff888113d0687f RDI: ffff888093d06880 RBP: ffff888093d06880 R08: 0000000000000001 R09: 0000000000000001 R10: ffff88804ec8eef0 R11: ffff88804ec8e640 R12: ffff888113d0687f R13: ffffffff869557c2 R14: ffff88804ef57a08 R15: 00000000000020c2 vsnprintf+0x1c4/0x1350 lib/vsprintf.c:2247 sprintf+0xa7/0xd0 lib/vsprintf.c:2383 proc_self_get_link+0xf7/0x1c0 fs/proc/self.c:24 get_link fs/namei.c:1092 [inline] link_path_walk+0xc3d/0x1080 fs/namei.c:2160 path_openat+0x167/0x2aa0 fs/namei.c:3568 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416861 RSP: 002b:00007fd13e9dabb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000509800 RCX: 0000000000416861 RDX: 00007fd13e9dabe3 RSI: 0000000000000002 RDI: 00007fd13e9dabd0 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000008 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c26 R14: 00000000004ce794 R15: 00007fd13e9db6d4 rcu_preempt kthread starved for 10488 jiffies! g2245 c2244 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1 rcu_preempt R running task 29904 8 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x4df/0xe50 kernel/time/timer.c:1746 rcu_gp_kthread+0xb3d/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404