rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=c7bc/1/0x4000000000000000 softirq=17425/17425 fqs=0
rcu: 	(detected by 1, t=10505 jiffies, g=11161, q=244 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6577 Comm: syz.2.196 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:lock_release+0xd8/0x3e0
Code: 20 fa 48 c7 c7 dc d7 9c 8d e8 64 d3 dc 09 65 ff 05 0d 71 03 11 c7 44 24 20 01 00 00 00 83 3d 2e 58 06 0e 00 0f 84 96 01 00 00 <41> 8b 87 e8 0a 00 00 85 c0 0f 84 1d 01 00 00 4c 89 6c 24 18 48 89
RSP: 0018:ffffc90000007818 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000087 RCX: a2c647f8d625e500
RDX: 0000000000010000 RSI: ffffffff8d9cd7dc RDI: ffffffff8be33c00
RBP: ffffc90000007918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: dffffc0000000000
R13: ffffffff81ada71e R14: ffff88804b027a98 R15: ffff88810770d640
FS:  00007f9c620086c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3241fff8 CR3: 0000000026184000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __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:unwind_next_frame+0x223/0x2390
Code: 86 65 18 00 00 44 89 f8 4c 8d 2c 85 54 4a e0 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 <44> 89 f8 ff c0 48 8d 2c 85 54 4a e0 90 48 89 e8 48 c1 e8 03 0f b6
RSP: 0018:ffffc90006c06d18 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: a2c647f8d625e500
RDX: 00000000000a7e05 RSI: ffffffff8be33be0 RDI: ffffffff8be33ba0
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc90006c06e38 R11: ffffffff81ac4b00 R12: ffffffff89a101ee
R13: 000000000018a630 R14: ffffc90006c06de8 R15: 000000000008a101
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 ref_tracker_free+0xef/0x7d0
 ethnl_default_dumpit+0x3c1/0x600
 genl_dumpit+0x10b/0x1b0
 netlink_dump+0x6e4/0xe90
 __netlink_dump_start+0x5cb/0x7e0
 genl_family_rcv_msg_dumpit+0x1e7/0x2c0
 genl_rcv_msg+0x5da/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/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: 0033:0x7f9c6118ec29
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:00007f9c62008038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9c613d5fa0 RCX: 00007f9c6118ec29
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f9c61211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c613d6038 R14: 00007f9c613d5fa0 R15: 00007ffce2ed58f8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g11161 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=4674
rcu: rcu_preempt kthread starved for 10505 jiffies! g11161 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:27432 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+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
