Ubuntu 18.10 regression: nvidia driver does not work

Problems started after upgrade to 18.10 and first reboot.
Symptoms:
* Login screen appears
* After providing credentials desktop does not start

Part of dmesg:
-------------------------------------------------
...
[ 10.482929] resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000c0000-0x000dffff window]
[ 10.483149] caller os_map_kernel_space.part.9+0xd4/0x120 [nvidia] mapping multiple BARs
[ 10.801510] ------------[ cut here ]------------
[ 10.801512] Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLUB object 'nvidia_stack_cache' (offset 11440, size 3)!
[ 10.801522] WARNING: CPU: 3 PID: 1188 at mm/usercopy.c:81 usercopy_warn+0x81/0xa0
[ 10.801523] Modules linked in: snd_hda_codec_hdmi binfmt_misc nvidia_uvm(POE) nls_iso8859_1 wmi_bmof mxm_wmi intel_rapl x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc nvidia_drm(POE) aesni_intel nvidia_modeset(POE) aes_x86_64 crypto_simd cryptd glue_helper nvidia(POE) intel_cstate snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm arc4 snd_seq_midi snd_seq_midi_event snd_rawmidi intel_rapl_perf ath9k snd_seq ath9k_common ath9k_hw drm_kms_helper joydev ath snd_seq_device input_leds snd_timer mac80211 drm snd cfg80211 ipmi_devintf ir_rc6_decoder ipmi_msghandler fb_sys_fops syscopyarea soundcore mei_me sysfillrect sysimgblt mei rc_rc6_mce video nuvoton_cir mac_hid rc_core wmi sch_fq_codel
[ 10.801559] nct6775 hwmon_vid coretemp parport_pc sunrpc ppdev lp parport ip_tables x_tables autofs4 hid_logitech_hidpp hid_logitech_dj hid_generic usbhid hid gpio_ich ahci r8169 libahci lpc_ich mii
[ 10.801572] CPU: 3 PID: 1188 Comm: Xorg Tainted: P OE 4.18.0-8-generic #9-Ubuntu
...
-------------------------------------------------

Extra info for Bug 1796433

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: linux-image-4.18.0-8-generic 4.18.0-8.9
ProcVersionSignature: Ubuntu 4.18.0-8.9-generic 4.18.7
Uname: Linux 4.18.0-8-generic x86_64
ApportVersion: 2.20.10-0ubuntu11
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: alexei 2824 F.... pulseaudio
 /dev/snd/controlC0: alexei 2824 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 8 19:47:11 2018
HibernationDevice: RESUME=UUID=45af239b-c597-45a1-bb72-3ba25b5ee546
InstallationDate: Installed on 2016-01-06 (1005 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcFB: 0 EFI VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-8-generic root=UUID=d4f27b9e-0cff-49e1-8392-a41aa520bd85 ro noprompt persistent quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.18.0-8-generic N/A
 linux-backports-modules-4.18.0-8-generic N/A
 linux-firmware 1.175
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: yes
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to cosmic on 2018-10-05 (2 days ago)
dmi.bios.date: 09/16/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P1.10
dmi.board.name: HM65-MXM
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.10:bd09/16/2011:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnHM65-MXM:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: To Be Filled By O.E.M.
dmi.product.sku: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.