rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=c91c/1/0x4000000000000000 softirq=51181/51181 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=46521, q=343 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13674 Comm: syz.4.2349 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:_raw_spin_unlock_irqrestore+0x93/0x110
Code: 75 08 e8 d0 e8 16 f6 4c 89 f7 e8 28 80 17 f6 f7 c3 00 02 00 00 74 05 e8 db e5 40 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <f6> 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e8
RSP: 0018:ffffc90000007880 EFLAGS: 00000046
RAX: 1ffffffff1c351e7 RBX: 0000000000000802 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88804b027ac0
RBP: ffffc90000007918 R08: ffff88804b027ac3 R09: 1ffff11009604f58
R10: dffffc0000000000 R11: ffffed1009604f59 R12: dffffc0000000000
R13: ffff88804b027b40 R14: ffff88804b027ac0 R15: 1ffff92000000f10
FS:  00007f2d200706c0(0000) GS:ffff8880b83e0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 0000000039e2c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3b8/0x500
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+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 cb e6 0a f6 e8 36 51 42 f6 fb bf 01 00 00 00 <e8> 5b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc900067f7060 EFLAGS: 00000286
RAX: a47dc91add280200 RBX: 0000000000000000 RCX: a47dc91add280200
RDX: 0000000000000006 RSI: ffffffff8dbc0fba RDI: 0000000000000001
RBP: ffffc900067f7110 R08: ffffffff8fc43c37 R09: 1ffffffff1f88786
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000cfee0c
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 cb 8f 26 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900067f71d8 EFLAGS: 00000206
RAX: a47dc91add280200 RBX: 0000000000000000 RCX: a47dc91add280200
RDX: 0000000000000000 RSI: ffffffff8ddb21f6 RDI: ffffffff8c038200
RBP: ffffffff8173bd25 R08: 0000000000000000 R09: ffffffff8173bd25
R10: ffffc900067f7398 R11: ffffffff81ac44a0 R12: 0000000000000002
R13: ffffffff8e33d660 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x367/0x6e0
 __kernfs_new_node+0xd7/0x7e0
 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+0xcde/0xf30
 kernfs_iop_mkdir+0x211/0x350
 vfs_mkdir+0x306/0x510
 do_mkdirat+0x247/0x590
 __x64_sys_mkdirat+0x87/0xa0
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d1f18eba9
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:00007f2d20070038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f2d1f3d5fa0 RCX: 00007f2d1f18eba9
RDX: 00000000000001ff RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f2d1f211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d1f3d6038 R14: 00007f2d1f3d5fa0 R15: 00007ffd1e662088
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g46521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=21612
rcu: rcu_preempt kthread starved for 10502 jiffies! g46521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:26984 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
