rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=c2c4/1/0x4000000000000000 softirq=36371/36375 fqs=0
rcu: 	(detected by 1, t=10506 jiffies, g=21245, q=827 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9285 Comm: syz.0.1268 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:kasan_check_range+0x1d3/0x2c0
Code: 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4e 5d 59 09 cc 45 84 ff 75 63 41
RSP: 0018:ffffc90000007cd0 EFLAGS: 00000056
RAX: ffffffff81ade201 RBX: 0000000000000000 RCX: ffffffff81ade237
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fa38330
RBP: 0000000000000000 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: 0000000000000001
R13: 0000000000000000 R14: fffffbfff1f47067 R15: 1ffffffff1f47066
FS:  0000000000000000(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62d371cfc8 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 enqueue_hrtimer+0x77/0x3a0
 __hrtimer_run_queues+0x656/0xc60
 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:unmap_page_range+0x1ed5/0x4370
Code: e8 e0 c3 19 00 48 8b bc 24 b8 00 00 00 4c 89 3f 48 8b 4c 24 68 48 89 cb 48 c1 eb 03 48 b8 00 00 00 00 00 fc ff df 80 3c 03 00 <74> 0f 48 8b 7c 24 68 e8 bf c2 19 00 48 8b 4c 24 68 48 8b 01 48 8b
RSP: 0018:ffffc9000307f3a0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 1ffff9200060ff0f RCX: ffffc9000307f878
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000307f870
RBP: ffffc9000307f650 R08: ffffea0000463107 R09: 1ffffd400008c620
R10: dffffc0000000000 R11: fffff9400008c621 R12: dffffc0000000000
R13: 00007f62d29ab000 R14: 00000000118c4000 R15: 00007f62d2400000
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f62d298ebe9
Code: Unable to access opcode bytes at 0x7f62d298ebbf.
RSP: 002b:00007f62d371d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f62d2bb5fa8 RCX: 00007f62d298ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f62d2bb5fa8
RBP: 00007f62d2bb5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62d2bb6038 R14: 00007ffd3758bd00 R15: 00007ffd3758bde8
 </TASK>
rcu: rcu_preempt kthread starved for 10506 jiffies! g21245 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:27496 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: 1 UID: 0 PID: 9281 Comm: syz.3.1265 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 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 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 45 5e
RSP: 0018:ffffc90002e0f560 EFLAGS: 00000293
RAX: ffffffff81b44ceb RBX: 1ffff11009608341 RCX: ffff888023ba3980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e0f6e0 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  00007fde495e06c0(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003200 CR3: 0000000123312000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 vms_clear_ptes+0x42c/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: 0033:0x7fde4878ec77
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:00007fde495dfe18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fde4878ec77
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007fde3e400000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005108
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fde495dfef0 R14: 00007fde495dfeb0 R15: 00007fde3e400000
 </TASK>
