rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=a254/1/0x4000000000000000 softirq=17412/17412 fqs=3621
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   961823          0            0
rcu: 	cputime:    26298      26180           98   ==> 52480(ms)
rcu: 	(t=10500 jiffies g=8873 q=2440 ncpus=2)
CPU: 1 UID: 0 PID: 6674 Comm: syz.0.250 Not tainted 6.16.0-rc6-syzkaller-00411-g95993dc3039e-dirty #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+0x87/0x4c0
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 62 2c f8 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:ffffc900001e03e0 EFLAGS: 00000206
RAX: 8a3e1d62942cbb00 RBX: 1ffff9200003c084 RCX: 8a3e1d62942cbb00
RDX: 0000000000000002 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: ffffc900001e04d8 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007f520d45e6c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f520c7a5db8 CR3: 000000010f6c2000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
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_irq_work+0xa3/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20
RIP: 0010:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 8b 1d 21 f6 e8 c6 f0 57 f6 fb bf 01 00 00 00 <e8> 1b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc9000290f820 EFLAGS: 00000282
RAX: 8a3e1d62942cbb00 RBX: 0000000000000000 RCX: 8a3e1d62942cbb00
RDX: 0000000000000007 RSI: ffffffff8d99883e RDI: 0000000000000001
RBP: ffffc9000290f8c0 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000521f04
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:qlist_free_all+0x31/0x140
Code: 41 54 53 48 8b 2f 48 85 ed 0f 84 14 01 00 00 49 89 f6 48 89 fb 45 31 ed 49 89 ef 4d 89 f4 4d 85 f6 75 40 4c 8b 25 07 05 98 0b <4c> 89 ff e8 b7 0e 51 ff 48 c1 e8 06 48 83 e0 c0 49 8b 4c 04 08 f6
RSP: 0018:ffffc9000290f980 EFLAGS: 00000246
RAX: 8a3e1d62942cbb00 RBX: ffffc9000290f9b8 RCX: 0000000000150001
RDX: 0000000000150002 RSI: ffffea0000832980 RDI: ffffffff00000000
RBP: ffff888106b5c6c0 R08: 0000000000000001 R09: ffff888020ca7e00
R10: 0000000000000000 R11: fffffbfff1f43d1f R12: ffffea0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888106b5c6c0
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_node_track_caller_noprof+0x216/0x4e0
 kstrdup+0x42/0x100
 __kernfs_new_node+0x9c/0x7e0
 kernfs_new_node+0x102/0x210
 kernfs_create_dir_ns+0x44/0x130
 cgroup_mkdir+0x39f/0xe60
 kernfs_iop_mkdir+0x211/0x350
 vfs_mkdir+0x306/0x510
 do_mkdirat+0x247/0x590
 __x64_sys_mkdirat+0x87/0xa0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f520c58e9a9
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:00007f520d45e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f520c7b6160 RCX: 00007f520c58e9a9
RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f520c610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f520c7b6160 R15: 00007fffeecb8388
 </TASK>
sched: DL replenish lagged too much
