rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=496c/1/0x4000000000000000 softirq=13724/13724 fqs=5001
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1272100          0            0
rcu: 	cputime:     7368      45111           37   ==> 52480(ms)
rcu: 	(t=10500 jiffies g=10593 q=6737 ncpus=2)
CPU: 0 UID: 0 PID: 5848 Comm: syz.2.37 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+0x1a/0x470
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 50 65 8b 2d de ba 93 11 f7 c5 00 00 f0 00 74 14 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 89
RSP: 0018:ffffc90000007570 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000000000101
RDX: 0000000000000002 RSI: ffffffff8dfe0684 RDI: ffffffff8c2a9f80
RBP: ffff88818dc24000 R08: ffffffff9032ddf7 R09: 1ffffffff2065bbe
R10: dffffc0000000000 R11: fffffbfff2065bbf R12: ffffffff8e95f878
R13: dffffc0000000000 R14: ffff88812103c1d8 R15: 1ffff1102420783b
FS:  00007fa57e5b36c0(0000) GS:ffff88818dc24000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000116cf6000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x83/0xe0
 unwind_next_frame+0x1baf/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x355/0x610
 __alloc_skb+0x276/0x7a0
 ndisc_alloc_skb+0xa0/0x480
 ndisc_send_rs+0x288/0x6b0
 addrconf_rs_timer+0x2d2/0x6c0
 call_timer_fn+0x192/0x5e0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x225/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:finish_task_switch+0x417/0xc60
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 a3 88 21 0a e8 1e ac 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc90006787c60 EFLAGS: 00000206
RAX: 00000000000003ff RBX: ffff88812103bf20 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8dfe0684 RDI: ffffffff8c2a9f80
RBP: ffffc90006787cb0 R08: ffffffff9032ddf7 R09: 1ffffffff2065bbe
R10: dffffc0000000000 R11: fffffbfff2065bbf R12: ffff888105371dc0
R13: ffff888105371dc0 R14: dffffc0000000000 R15: 1ffff110242077e4
 __schedule+0x17e1/0x56c0
 schedule+0x164/0x2b0
 irqentry_exit+0x291/0x8f0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7fa57d662e94
Code: 8b 74 de 30 48 83 c3 01 e8 49 e6 fe ff 41 39 5e 2c 7f d3 31 c0 48 8d 3d f6 cb 1e 00 e8 35 e6 fe ff 48 8b 44 24 08 44 8b 60 78 <c6> 80 e8 00 00 00 00 45 85 e4 0f 8e ac 03 00 00 8b 88 80 00 00 00
RSP: 002b:00007fa57e5b3050 EFLAGS: 00000206
RAX: 00007fa57da15fa0 RBX: 0000000000000003 RCX: 00007fa57d84af98
RDX: 000000000000231b RSI: 0000000000000000 RDI: 00007fa57d84fa7c
RBP: 00007fa57d832e6f R08: 000000000b11ae58 R09: 3fffffffffffffff
R10: 4000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa57da16038 R14: 00007fa57da15fa0 R15: 00007fff02f9d698
 </TASK>
sched: DL replenish lagged too much
