rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=7701, q=504 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294954397-4294943895), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g7701 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=3123
rcu: rcu_preempt kthread starved for 10502 jiffies! g7701 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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:R stack:27184 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
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>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5983 Comm: syz.0.12 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_acquire+0x460/0xd20
Code: ff ff ff 0f 4c e9 ff c5 45 8d 7c 24 01 49 ff cc 44 89 f9 83 c1 fe 78 44 44 89 e3 81 e3 ff ff ff 7f 83 f9 31 73 1d 48 8d 0c 9b <8b> 8c cf 50 0b 00 00 31 c1 41 ff cf 49 ff cc f7 c1 00 60 00 00 74
RSP: 0018:ffffc900001e0750 EFLAGS: 00000097
RAX: 00000000000c4068 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000004000 RDI: ffff88801bf11d00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ae2edb
R10: dffffc0000000000 R11: ffffed1026cc4f59 R12: 0000000000000000
R13: 0000000000000002 R14: ffff88801bf12858 R15: 0000000000000002
FS:  00007f6a4c3f66c0(0000) GS:ffff8881a3a03000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a4c3f5fc8 CR3: 0000000027d78000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/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:unwind_next_frame+0x3a6/0x2390
Code: 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 80 19 00 00 41 0f b6 44 24 01 83 e0 07 0f 84 75 15 00 00 83 f8 01 4c 8b 7c 24 48 <48> bd 00 00 00 00 00 fc ff df 4c 8b 64 24 20 4c 8b 6c 24 50 0f 84
RSP: 0018:ffffc900042b73b8 EFLAGS: 00000202
RAX: 0000000000000002 RBX: ffffffff90313944 RCX: ffffffff90313948
RDX: ffffffff90da4f40 RSI: ffffffff90da4f40 RDI: ffffffff8c03d480
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff81742d25
R10: ffffc900042b74d8 R11: ffffffff81acd5a0 R12: ffffffff90da4f44
R13: ffffffff90da4f45 R14: ffffc900042b7488 R15: ffffffff81742d25
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kmem_cache_free+0x19b/0x690
 netlink_recvmsg+0x5b2/0xa30
 sock_recvmsg+0x22c/0x270
 ____sys_recvmsg+0x1c9/0x460
 ___sys_recvmsg+0x1b5/0x510
 __x64_sys_recvmsg+0x198/0x260
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a4e18ec29
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:00007f6a4c3f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f6a4e3d5fa0 RCX: 00007f6a4e18ec29
RDX: 0000000000010100 RSI: 0000200000000380 RDI: 0000000000000007
RBP: 00007f6a4e211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a4e3d6038 R14: 00007f6a4e3d5fa0 R15: 00007ffd30fda418
 </TASK>
