rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=59185, q=441 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4295020260-4295009760), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g59185 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26728 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>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16646 Comm: syz.4.2950 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:strlen+0x32/0x70
Code: 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 11 <48> ff c3 49 8d 47 01 42 80 7c 3f 01 00 75 de eb 19 89 d9 80 e1 07
RSP: 0018:ffffc900000076f8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8b8cf50a RCX: ffff888105439cc0
RDX: ffffffff81ada91e RSI: ffff88804b027a98 RDI: ffffffff8b8cf500
RBP: ffffc90000007808 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: 1ffff92000000eec
R13: ffffffff81ada91e R14: dffffc0000000000 R15: 0000000000000009
FS:  00007f5d7e85c6c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f40171a7cc0 CR3: 0000000125124000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_trace_lock+0xc2/0x3b0
 lock_release+0x3b2/0x3e0
 _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:finish_task_switch+0x26b/0x950
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 df c4 eb 09 e8 8a 41 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900024ff2d8 EFLAGS: 00000286
RAX: d4e000aee14f5700 RBX: 0000000000000000 RCX: d4e000aee14f5700
RDX: 0000000000000000 RSI: ffffffff8d9ba186 RDI: ffffffff8be33e00
RBP: ffffc900024ff330 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff888105439cc0
R13: dffffc0000000000 R14: ffff888021483980 R15: ffff88804b03ab58
 __schedule+0x17a0/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 __skb_wait_for_more_packets+0x3a2/0x580
 skb_recv_datagram+0x119/0x190
 rawv6_recvmsg+0x25e/0xca0
 sock_common_recvmsg+0x109/0x1b0
 sock_recvmsg+0x22c/0x270
 ____sys_recvmsg+0x1c9/0x460
 ___sys_recvmsg+0x1b5/0x510
 __x64_sys_recvmsg+0x198/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5d7d98eba9
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:00007f5d7e85c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f5d7dbd5fa0 RCX: 00007f5d7d98eba9
RDX: 0000000000010000 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f5d7da11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5d7dbd6038 R14: 00007f5d7dbd5fa0 R15: 00007ffd4a8c6738
 </TASK>
