GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=32505, q=1180 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294964472-4294953970), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g32505 f0x2 RCU_GP_WAIT_FQS(5) ->state=R
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=9854
rcu: rcu_preempt kthread starved for 10502 jiffies! g32505 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 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: 9886 Comm: syz.2.1726 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:__lock_acquire+0x2f8/0x2e50
Code: 89 54 c5 20 48 8b 94 24 28 01 00 00 49 89 54 c5 08 4d 89 5c c5 10 48 8b 94 24 20 01 00 00 49 89 54 c5 18 65 8b 15 94 c2 f1 11 <31> f6 85 d2 40 0f 95 c6 31 d2 83 bf 8c 0b 00 00 00 0f 95 c2 c1 e2
RSP: 0018:ffffc90000a38b10 EFLAGS: 00000002
RAX: 0000000000000014 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000000001 RSI: 0000000000000007 RDI: ffff888112893c00
RBP: 0000000000000000 R08: 0000000019ff112f R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: 0000000000000000
R13: ffff8881128947b0 R14: 0000000000000002 R15: 0000000000000004
FS:  00007f248c7516c0(0000) GS:ffff8882a8cd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b46a27dac CR3: 0000000112f8c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x115/0x350
 advance_sched+0xa04/0xc80
 __hrtimer_run_queues+0x3bc/0xa10
 hrtimer_interrupt+0x4cd/0xaa0
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x232/0x350
Code: ff ff ff e8 b0 5b 41 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 02 87 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 87 37 da
RSP: 0018:ffffc90007ce7310 EFLAGS: 00000292
RAX: f9b1f89d2993eb00 RBX: 0000000000000000 RCX: 8000000000000001
RDX: 00000000ae78f4f6 RSI: ffffffff8e6fd21d RDI: ffffffff8c6d9c80
RBP: ffff888112893c00 R08: 7f00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: ffffffff8ed5c6e0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
 page_table_check_clear+0x1ed/0x590
 __zap_vma_range+0x3a12/0x4f80
 unmap_vmas+0x390/0x550
 exit_mmap+0x293/0x9f0
 __mmput+0x118/0x420
 exit_mm+0x221/0x2d0
 do_exit+0x6cd/0x2360
 do_group_exit+0x22d/0x2f0
 get_signal+0x121b/0x12c0
 arch_do_signal_or_restart+0xbb/0x860
 exit_to_user_mode_loop+0x10e/0x770
 do_syscall_64+0x328/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f248b79e159
Code: Unable to access opcode bytes at 0x7f248b79e12f.
RSP: 002b:00007f248c7510e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f248ba25fa8 RCX: 00007f248b79e159
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f248ba25fa8
RBP: 00007f248ba25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f248ba26038 R14: 00007fff793accf0 R15: 00007fff793acdd8
 </TASK>
