rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=260c/0/0x1 softirq=175952/175952 fqs=280
rcu: 	(detected by 0, t=10506 jiffies, g=186869, q=664 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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:__hrtimer_run_queues+0x696/0xc60
Code: 24 18 48 8b 74 24 30 42 0f b6 04 2e 84 c0 48 8b 54 24 20 0f 85 9c 01 00 00 ff 02 42 0f b6 04 2e 84 c0 0f 85 b6 01 00 00 ff 02 <48> 8b 44 24 48 42 80 3c 28 00 74 08 48 89 df e8 36 66 75 00 4c 39
RSP: 0018:ffffc900001e0d40 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff888136627cc8 RCX: 0000000000000000
RDX: ffff888136627c90 RSI: 1ffff11026cc4f92 RDI: ffff8881072a2340
RBP: ffffc900001e0e90 R08: ffff8881072a2357 R09: 0000000000000000
R10: ffff8881072a2340 R11: ffffed1020e5446b R12: ffff8881072a2340
R13: dffffc0000000000 R14: ffff888136627cd8 R15: ffff888136627c80
FS:  0000000000000000(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbc3cb42fc8 CR3: 000000003a24e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 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:pv_native_safe_halt+0x13/0x20
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d f3 86 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000177de0 EFLAGS: 00000282
RAX: b292837cbd12d700 RBX: ffffffff819683c8 RCX: b292837cbd12d700
RDX: 0000000000000001 RSI: ffffffff8d9b77d3 RDI: ffffffff8be33680
RBP: ffffc90000177f20 R08: ffff888136632f9b R09: 1ffff11026cc65f3
R10: dffffc0000000000 R11: ffffed1026cc65f4 R12: ffffffff8fa38a30
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110200d4000
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>
rcu: rcu_preempt kthread starved for 9105 jiffies! g186869 f0x0 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:27160 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5774 Comm: syz-executor 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:smp_call_function_many_cond+0xd33/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 06 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 b1 5e 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 95 5e
RSP: 0018:ffffc90002e0f160 EFLAGS: 00000293
RAX: ffffffff81b44cfb RBX: 1ffff11026cc7f61 RCX: ffff888028443980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e0f2e0 R08: ffffffff8fa38a37 R09: 1ffffffff1f47146
R10: dffffc0000000000 R11: fffffbfff1f47147 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  0000555561d1a500(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98d3350000 CR3: 000000010ffb0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 flush_tlb_batched_pending+0x8a/0xe0
 unmap_page_range+0xcae/0x4370
 unmap_vmas+0x399/0x580
 vms_clear_ptes+0x35c/0x540
 vms_complete_munmap_vmas+0x206/0x8a0
 do_vmi_align_munmap+0x358/0x420
 do_vmi_munmap+0x253/0x2e0
 __vm_munmap+0x23b/0x3d0
 __x64_sys_munmap+0x60/0x70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff09098ec77
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 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:00007fff702c9178 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00007ff091811000 RCX: 00007ff09098ec77
RDX: 00007ff09098cdf0 RSI: 0000000000009000 RDI: 00007ff091811000
RBP: 0000000000009000 R08: 00007fff702c9210 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 00000000000073c8
R13: 0000555561d2eb6c R14: 00007fff702c9210 R15: 0000000000000000
 </TASK>
