rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=968c/1/0x4000000000000000 softirq=67274/67478 fqs=5167
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   923619        795            0
rcu: 	cputime:    32841      19644           55   ==> 52490(ms)
rcu: 	(t=10501 jiffies g=61169 q=1801 ncpus=2)
CPU: 0 UID: 0 PID: 17906 Comm: syz.2.3420 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_read_unlock_special+0x87/0x5e0
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 c2 24 f9 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900000073e0 EFLAGS: 00000206
RAX: 8b6615e51ab34600 RBX: 1ffff92000000e84 RCX: 8b6615e51ab34600
RDX: 0000000000000002 RSI: ffffffff8d9b6a61 RDI: ffffffff8be33380
RBP: ffffc900000074d8 R08: ffffffff8fa38137 R09: 1ffffffff1f47026
R10: dffffc0000000000 R11: fffffbfff1f47027 R12: ffffffff8e13f200
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
FS:  00007fd3ef6c26c0(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000202f6000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000f0602
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 ndisc_alloc_skb+0x9f/0x480
 ndisc_send_rs+0x2b5/0x630
 addrconf_rs_timer+0x369/0x670
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:rcu_read_unlock_special+0x87/0x5e0
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 c2 24 f9 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc9000293ebe0 EFLAGS: 00000206
RAX: 8b6615e51ab34600 RBX: 1ffff92000527d84 RCX: 8b6615e51ab34600
RDX: 0000000000000000 RSI: ffffffff8d9b6a61 RDI: ffffffff8be33380
RBP: ffffc9000293ecd8 R08: ffffffff8fa38137 R09: 1ffffffff1f47026
R10: dffffc0000000000 R11: fffffbfff1f47027 R12: ffffffff8e13f200
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __reset_page_owner+0x71/0x1f0
 __free_frozen_pages+0xbc4/0xd30
 pagetable_dtor_free+0x2d2/0x3b0
 __mmdrop+0xb5/0x580
 finish_task_switch+0x3ee/0x950
 __schedule+0x17a0/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:preempt_schedule_thunk+0x0/0x30
Code: e8 8b 00 48 c7 c0 00 58 80 8b e9 0b 65 48 0a cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 e8 2a a8 46 0a
RSP: 0018:ffffc9000293f618 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000a02 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8d9b6a61 RDI: 00000000ffffffff
RBP: ffffc9000293f6a0 R08: ffffffff8fa38137 R09: 1ffffffff1f47026
R10: dffffc0000000000 R11: fffffbfff1f47027 R12: dffffc0000000000
R13: ffff8881103cd170 R14: ffffffff99cc8838 R15: 1ffff92000527ec4
 _raw_spin_unlock_irqrestore+0xfd/0x110
 debug_check_no_obj_freed+0x451/0x470
 kmem_cache_free+0x113/0x400
 netlink_unicast+0x837/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd3ee78ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fd3ef6c2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd3ee9b5fa0 RCX: 00007fd3ee78ebe9
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000008
RBP: 00007fd3ee811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd3ee9b6038 R14: 00007fd3ee9b5fa0 R15: 00007ffc0f8438e8
 </TASK>
sched: DL replenish lagged too much
