Got something similar:
[ 2570.763287] PANIC: double fault, error_code: 0x0
[ 2570.764564] Kernel panic - not syncing: Machine halted.
[ 2570.765428] CPU: 0 PID: 22272 Comm: as Not tainted 4.15.0-041500-generic #201801282230
[ 2570.767059] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
[ 2570.768815] Call Trace:
[ 2570.769263]  <#DF>
[ 2570.769643]  dump_stack+0x63/0x8b
[ 2570.770251]  panic+0xe4/0x234
[ 2570.770787]  df_debug+0x2d/0x30
[ 2570.771342]  do_double_fault+0xa1/0x130
[ 2570.772031]  double_fault+0x22/0x30
[ 2570.772583] RIP: 0010:clear_page_erms+0x7/0x10
[ 2570.773303] RSP: 0018:ffffb98e428d78a0 EFLAGS: 00010246
[ 2570.774242] RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000001000
[ 2570.775515] RDX: ffff90327df4c500 RSI: ffffdb5084a10fc0 RDI: ffff90332843f000
[ 2570.776837] RBP: ffffb98e428d79b8 R08: 0000000000000000 R09: ffffdb5084a11000
[ 2570.778144] R10: 0000000000000000 R11: ffffb98e428d7cc0 R12: ffff90333ffd2d00
[ 2570.779437] R13: ffffb98e428d79c8 R14: 00000000014280ca R15: ffffdb5084a10fc0
[ 2570.780712]  </#DF>
[ 2570.781098]  ? get_page_from_freelist+0xf0d/0x1400
[ 2570.781958]  ? try_to_wake_up+0x59/0x480
[ 2570.782709]  __alloc_pages_nodemask+0xfb/0x280
[ 2570.783652]  alloc_pages_vma+0x88/0x1f0
[ 2570.784354]  __handle_mm_fault+0x938/0x11e0
[ 2570.785128]  handle_mm_fault+0xb1/0x200
[ 2570.785814]  __do_page_fault+0x257/0x4d0
[ 2570.786528]  do_page_fault+0x2e/0xd0
[ 2570.787171]  do_async_page_fault+0x51/0x80
[ 2570.787902]  async_page_fault+0x2c/0x60
[ 2570.788589] RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20
[ 2570.789624] RSP: 0018:ffffb98e428d7cd8 EFLAGS: 00050206
[ 2570.790584] RAX: 00007f5c60aff010 RBX: 0000000004a26f00 RCX: 0000000000000010
[ 2570.791858] RDX: 0000000000001000 RSI: ffff9033289bcff0 RDI: 00007f5c60aff000
[ 2570.793076] RBP: ffffb98e428d7ce0 R08: ffffb98e428d7e50 R09: ffffdb5084a26f00
[ 2570.794161] R10: 0000000000000040 R11: ffffb98e428d7cc0 R12: 0000000000001000
[ 2570.795252] R13: ffffb98e428d7e88 R14: ffff9033289bc000 R15: 0000000000001000
[ 2570.796339]  ? copyout+0x26/0x30
[ 2570.796867]  copy_page_to_iter+0x10c/0x2f0
[ 2570.797521]  generic_file_read_iter+0x44b/0xbe0
[ 2570.798239]  ? page_cache_tree_insert+0xe0/0xe0
[ 2570.798969]  nfs_file_read+0x6e/0xc0 [nfs]
[ 2570.799667]  __vfs_read+0xee/0x160
[ 2570.800262]  vfs_read+0x8e/0x130
[ 2570.800817]  SyS_read+0x55/0xc0
[ 2570.801358]  entry_SYSCALL_64_fastpath+0x24/0x87
[ 2570.802156] RIP: 0033:0x7f5c614b4260
[ 2570.802768] RSP: 002b:00007ffc41b1b638 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 2570.804043] RAX: ffffffffffffffda RBX: 00007f5c61781b20 RCX: 00007f5c614b4260
[ 2570.805242] RDX: 0000000000100000 RSI: 00007f5c60ada010 RDI: 0000000000000003
[ 2570.806445] RBP: 0000000000100010 R08: 00000000016bf380 R09: 0000000000000054
[ 2570.807645] R10: 00007f5c61db8700 R11: 0000000000000246 R12: 0000000000101000
[ 2570.808845] R13: 00007f5c61781b78 R14: 0000000000001000 R15: 0000000000000040
[ 2570.810251] Kernel Offset: 0x2d400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 2570.812045] ---[ end Kernel panic - not syncing: Machine halted.