Screen freeze after GPUWatchDog segfault in chrome based browsers

I just updated to the Nvidia 450 drivers today as part of the regular updates released today.

My computer froze when the Chrome and Brave browsers both had the GPU watchdog segfault:

```
Sep 21 18:55:50 nopal /usr/lib/gdm3/gdm-x-session[6431]: (WW) NVIDIA(0): WAIT (2-S, 17, 0x643f79, 0x00003f70, 0x000049d4)
Sep 21 18:55:53 nopal kernel: GpuWatchdog[12519]: segfault at 0 ip 000055f768df0182 sp 00007f910e3d3390 error 6 in brave[55f763d38000+8372000]
Sep 21 18:55:53 nopal kernel: Code: 89 de e8 81 a4 75 ff 80 7d c7 00 79 09 48 8b 7d b0 e8 52 2e 62 fe 41 8b 84 24 e0 00 00 00 89 45 b0 48 8d 7d b0 e8 4e 36 4e fb <c7> 04 25 00 00 00 00 37 13 00 00 48 83 c4 48 5b 41 5c 41 5d 41 5e
Sep 21 18:55:53 nopal systemd[1]: Starting Process error reports when automatic reporting is enabled...
Sep 21 18:55:57 nopal /usr/lib/gdm3/gdm-x-session[6431]: (WW) NVIDIA(0): WAIT (1-S, 17, 0x643f79, 0x00003f70, 0x000049d4)
Sep 21 18:55:58 nopal whoopsie-upload-all[72517]: Collecting info for /var/crash/_opt_brave.com_brave_brave.1000.crash...
Sep 21 18:55:58 nopal whoopsie-upload-all[72517]: Marking /var/crash/_opt_brave.com_brave_brave.1000.crash for whoopsie upload
Sep 21 18:55:58 nopal whoopsie-upload-all[72517]: All reports processed
Sep 21 18:55:58 nopal systemd[1]: apport-autoreport.service: Succeeded.
Sep 21 18:55:58 nopal systemd[1]: Finished Process error reports when automatic reporting is enabled.
Sep 21 18:55:59 nopal whoopsie[2931]: [18:55:59] Parsing /var/crash/_opt_brave.com_brave_brave.1000.crash.
Sep 21 18:55:59 nopal whoopsie[2931]: [18:55:59] Uploading /var/crash/_opt_brave.com_brave_brave.1000.crash.
Sep 21 18:56:00 nopal whoopsie[2931]: [18:56:00] Sent; server replied with: No error
Sep 21 18:56:00 nopal whoopsie[2931]: [18:56:00] Response code: 200
Sep 21 18:56:00 nopal whoopsie[2931]: [18:56:00] Reported OOPS ID 6197b784-fc6e-11ea-a8fa-fa163e102db1
Sep 21 18:56:00 nopal systemd[1]: Starting Process error reports when automatic reporting is enabled...
Sep 21 18:56:00 nopal whoopsie-upload-all[73389]: /var/crash/_opt_brave.com_brave_brave.1000.crash already marked for upload, skipping
Sep 21 18:56:00 nopal whoopsie-upload-all[73389]: All reports processed
Sep 21 18:56:00 nopal systemd[1]: apport-autoreport.service: Succeeded.
Sep 21 18:56:00 nopal systemd[1]: Finished Process error reports when automatic reporting is enabled.
Sep 21 18:56:00 nopal /usr/lib/gdm3/gdm-x-session[6431]: (WW) NVIDIA(0): WAIT (2-S, 17, 0x643f5b, 0x00003f70, 0x000049d4)
Sep 21 18:56:02 nopal kernel: GpuWatchdog[10901]: segfault at 0 ip 000055bcb0e42a02 sp 00007fac3fb8a490 error 6 in chrome[55bcac5a8000+7bf3000]
Sep 21 18:56:02 nopal kernel: Code: 89 de e8 c1 8e 6f ff 80 7d c7 00 79 09 48 8b 7d b0 e8 42 e9 6b fe 41 8b 84 24 e0 00 00 00 89 45 b0 48 8d 7d b0 e8 ce df 9c fb <c7> 04 25 00 00 00 00 37 13 00 00 48 83 c4 48 5b 41 5c 41 5d 41 5e
Sep 21 18:56:02 nopal systemd[1]: Starting Process error reports when automatic reporting is enabled...
Sep 21 18:56:06 nopal whoopsie-upload-all[73402]: Collecting info for /var/crash/_opt_google_chrome_chrome.1000.crash...
Sep 21 18:56:06 nopal whoopsie-upload-all[73402]: Marking /var/crash/_opt_google_chrome_chrome.1000.crash for whoopsie upload
Sep 21 18:56:06 nopal whoopsie-upload-all[73402]: /var/crash/_opt_brave.com_brave_brave.1000.crash already marked for upload, skipping
Sep 21 18:56:06 nopal whoopsie-upload-all[73402]: All reports processed
Sep 21 18:56:06 nopal whoopsie[2931]: [18:56:06] Parsing /var/crash/_opt_google_chrome_chrome.1000.crash.
Sep 21 18:56:06 nopal systemd[1]: apport-autoreport.service: Succeeded.
Sep 21 18:56:06 nopal systemd[1]: Finished Process error reports when automatic reporting is enabled.
Sep 21 18:56:06 nopal whoopsie[2931]: [18:56:06] Uploading /var/crash/_opt_google_chrome_chrome.1000.crash.
Sep 21 18:56:07 nopal /usr/lib/gdm3/gdm-x-session[6431]: (WW) NVIDIA(0): WAIT (1-S, 17, 0x643f5b, 0x00003f70, 0x000049d4)
Sep 21 18:56:08 nopal whoopsie[2931]: [18:56:08] Sent; server replied with: No error
Sep 21 18:56:08 nopal whoopsie[2931]: [18:56:08] Response code: 200
Sep 21 18:56:08 nopal whoopsie[2931]: [18:56:08] Reported OOPS ID 65344bb5-fc6e-11ea-bb9d-fa163e983629
Sep 21 18:56:08 nopal systemd[1]: Starting Process error reports when automatic reporting is enabled...
Sep 21 18:56:08 nopal whoopsie-upload-all[74169]: /var/crash/_opt_google_chrome_chrome.1000.crash already marked for upload, skipping
Sep 21 18:56:08 nopal whoopsie-upload-all[74169]: /var/crash/_opt_brave.com_brave_brave.1000.crash already marked for upload, skipping
Sep 21 18:56:08 nopal whoopsie-upload-all[74169]: All reports processed
Sep 21 18:56:08 nopal systemd[1]: apport-autoreport.service: Succeeded.
Sep 21 18:56:08 nopal systemd[1]: Finished Process error reports when automatic reporting is enabled.
Sep 21 18:56:08 nopal systemd[1]: Starting Process error reports when automatic reporting is enabled...
Sep 21 18:56:08 nopal whoopsie-upload-all[74172]: /var/crash/_opt_google_chrome_chrome.1000.crash already marked for upload, skipping
Sep 21 18:56:08 nopal whoopsie-upload-all[74172]: /var/crash/_opt_brave.com_brave_brave.1000.crash already marked for upload, skipping
Sep 21 18:56:08 nopal whoopsie-upload-all[74172]: All reports processed
Sep 21 18:56:08 nopal systemd[1]: apport-autoreport.service: Succeeded.
Sep 21 18:56:08 nopal systemd[1]: Finished Process error reports when automatic reporting is enabled.
```

This issue did not happen under the 440 drivers, so seems to be related to the 450 drivers.

Ubuntu Release:
Description: Ubuntu 20.04.1 LTS
Release: 20.04

Nvidia Drivers:
450.66-0ubuntu0.20.04.1