rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=ba74/1/0x4000000000000000 softirq=16059/16059 fqs=0
rcu: 	(t=10500 jiffies g=8509 q=1933 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g8509 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2530
rcu: rcu_preempt kthread starved for 10501 jiffies! g8509 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:I stack:26632 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
CPU: 1 UID: 0 PID: 6491 Comm: syz.0.269 Not tainted 6.16.0-rc6-syzkaller-00434-gcd7c97f4584a-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 92 37 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: 0b6f85f7b6b15c00 RBX: 1ffff9200003c084 RCX: 0b6f85f7b6b15c00
RDX: 0000000000000002 RSI: ffffffff8d998701 RDI: ffffffff8be29f80
RBP: ffffc900001e04d0 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007fbb736826c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000028658000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 is_bpf_text_address+0x292/0x2b0
 kernel_text_address+0xa5/0xe0
 __kernel_text_address+0xd/0x40
 unwind_get_return_address+0x4d/0x90
 arch_stack_walk+0xfc/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 kmalloc_reserve+0xbd/0x290
 __alloc_skb+0x142/0x2d0
 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:__kernfs_new_node+0xc6/0x7e0
Code: 48 85 c0 0f 84 ec 00 00 00 48 89 c3 48 c7 c0 c0 fa bb 8d 48 c1 e8 03 42 80 3c 20 00 74 0c 48 c7 c7 c0 fa bb 8d e8 6a 3a c6 ff <48> 8b 3d c3 f3 5e 0b be c0 0d 00 00 e8 c9 46 bb ff 48 85 c0 0f 84
RSP: 0018:ffffc9000b8df760 EFLAGS: 00000246
RAX: 1ffffffff1b77f58 RBX: ffff88810ec72600 RCX: 0000000000000005
RDX: 000000000ec72604 RSI: ffffc9000b8dfa90 RDI: ffff88810ec72600
RBP: ffffc9000b8df8a8 R08: 00000000696b6c62 R09: 725f646563697672
R10: 65735f6f692e656c R11: 74746f7268742e6f R12: dffffc0000000000
R13: ffff88811badc5a0 R14: 1ffff9200171bef8 R15: ffff88801f1bd000
 kernfs_new_node+0x102/0x210
 __kernfs_create_file+0x4b/0x2e0
 cgroup_addrm_files+0x7f2/0xb20
 css_populate_dir+0x124/0x3d0
 cgroup_apply_control_enable+0x58a/0xa80
 cgroup_mkdir+0xc40/0xe60
 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: 0033:0x7fbb7278e9a9
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:00007fbb73682038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbb729b6080 RCX: 00007fbb7278e9a9
RDX: 00000000000001ff RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007fbb72810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbb729b6080 R15: 00007ffdac0ff848
 </TASK>
sched: DL replenish lagged too much
