rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=194173, q=143 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295066636-4295056134), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g194173 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:27328 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 550 Comm: syz.5.7399 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 fa 9b 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 97 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 89 97
RSP: 0018:ffffc9000a4ff580 EFLAGS: 00000293
RAX: ffffffff81b62417 RBX: 1ffff110478c8145 RCX: ffff8881108eba80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000a4ff700 R08: ffffffff8f822377 R09: 1ffffffff1f0446e
R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff88823c640a28
R13: dffffc0000000000 R14: ffff88812103bb00 R15: 0000000000000001
FS:  0000555592d74500(0000) GS:ffff88818e832000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1fa9073d58 CR3: 00000001a2ab6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x1280
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xf9/0x230
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x174/0xb10
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x850/0x25b0
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x2210/0x2210
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f9998f7c9
Code: Unable to access opcode bytes at 0x7f5f9998f79f.
RSP: 002b:00007ffd807b04f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5f9998f7c9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd807b055c R08: 00000011807b05ef R09: 00000000000927c0
R10: 0000000000000130 R11: 0000000000000246 R12: 00000000000008e8
R13: 00000000000927c0 R14: 00000000001226d9 R15: 00007ffd807b05b0
 </TASK>
