GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=bde4/1/0x4000000000000000 softirq=30552/30553 fqs=141
rcu: 	(detected by 1, t=10502 jiffies, g=29329, q=1138 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9022 Comm: syz.1.1432 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:preempt_count_sub+0x65/0x170
Code: ff ff ff 7f 39 cf 7f 2a 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 08 c8 74 58 65 8b 05 f4 16 d9 11 f7 df 65 01 3d eb 16 d9 11 <5b> 5d e9 54 9a 3f 0a cc 90 e8 0d c2 3d 03 85 c0 74 33 48 c7 c0 94
RSP: 0018:ffffc90000007da8 EFLAGS: 00000093
RAX: 0000000080010003 RBX: dffffc0000000000 RCX: 0000000000010000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffff88810fc69300 R08: ffffffff9aa1769b R09: 1ffffffff3542ed3
R10: dffffc0000000000 R11: fffffbfff3542ed4 R12: ffff8881210281c0
R13: dffffc0000000000 R14: ffffffff9aa17698 R15: ffff888121028450
FS:  00007fb0b220b6c0(0000) GS:ffff88818d949000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33423ffc CR3: 0000000115074000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x4c/0x80
 __hrtimer_run_queues+0x239/0xa10
 hrtimer_interrupt+0x448/0x910
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 9d 9b cf f5 f7 c3 00 02 00 00 74 05 e8 d0 79 fb f5 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c4 ad c0 f5 65 8b 05 0d c5 99 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc90009bd7c08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8e22faa3 RDI: 0000000000000001
RBP: ffffc90009bd7d30 R08: ffffffff9057c337 R09: 1ffffffff20af866
R10: dffffc0000000000 R11: fffffbfff20af867 R12: 0000000000000008
R13: dffffc0000000000 R14: ffff8881210281c0 R15: ffff8881210281c0
 clock_was_set+0x62b/0x7e0
 do_settimeofday64+0x34e/0x590
 __x64_sys_clock_settime+0x253/0x2a0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0b139e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb0b220b028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007fb0b1625fa0 RCX: 00007fb0b139e0d9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007fb0b1435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0b1626038 R14: 00007fb0b1625fa0 R15: 00007ffc058a2a98
 </TASK>
rcu: rcu_preempt kthread starved for 10220 jiffies! g29329 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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  running task     stack:28368 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 5641 Comm: udevd 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+0x11e6/0x15f0
Code: c0 75 7a 41 8b 1e 89 de 83 e6 01 31 ff e8 42 21 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 ee 1c 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 d3 1c 0c
RSP: 0018:ffffc900047df560 EFLAGS: 00000293
RAX: ffffffff81bace6d RBX: dffffc0000000000 RCX: ffff8881bf0a9e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900047df6a8 R08: ffffffff9057c337 R09: 1ffffffff20af866
R10: dffffc0000000000 R11: fffffbfff20af867 R12: 1ffff11024208611
R13: ffff88823c63c448 R14: ffff888121043088 R15: 0000000000000000
FS:  00007ff6bdbf8c80(0000) GS:ffff8882a8f49000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bf03c92200 CR3: 0000000171ca0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x5c4/0x1090
 tlb_flush_mmu+0x1af/0xa30
 tlb_finish_mmu+0xf4/0x220
 unmap_region+0x2a5/0x330
 vms_complete_munmap_vmas+0x427/0xbe0
 do_vmi_align_munmap+0x3b7/0x4b0
 do_vmi_munmap+0x252/0x2d0
 __vm_munmap+0x241/0x3e0
 __x64_sys_munmap+0x60/0x70
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6bdd1d817
Code: ff ff 76 10 48 8b 15 10 36 0d 00 f7 d8 64 89 02 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 35 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007fff5ec82998 EFLAGS: 00000206 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 000055bed50595b0 RCX: 00007ff6bdd1d817
RDX: 000000055bf03c80 RSI: 0000000000906623 RDI: 00007ff6bd200000
RBP: 000055bf03c7ace0 R08: 0000000000000007 R09: 5a75ca13fa501d7a
R10: 00000000ffffffff R11: 0000000000000206 R12: 000055bed50595e8
R13: 00007fff5ec82a18 R14: 0000000000000001 R15: 000055bf03c6a910
 </TASK>
