Kernel Oops - unable to handle kernel paging request at ffffc90000d6e808; IP [<ffffffffc0a80f12>] iwl_trans_pcie_read32+0x12/0x20 [iwlwifi]

[Zhivomira P. Ilieva]

After using my computer (Dell Inspiron 3576, running Ununtu 16.04.6 LTS) for a while the wi-fi suddenly stops working. The rest of my apps and programs continue to run smoothly. However, when I open "System Settings" and then try to open "Network", the computer hangs and in order to get it working again I have to reboot it. The reboot takes forever; meanwhle, I get a black screen with this message:
[75873.475364] BUG: unable to handle kernel paging request at ffffc90000d6e808
[............] IP [<ffffffffc0a80f1 fffffc0a80f12>] iwl_trans_pcie_read32+0x12/0x20 [iwlwifi]
PGD 2569aa067 PUD 2569ab067 PMD 255a96067 PTE 0
Oops: 0000 [#1] SMP

Full error readout in the attached photos.

Btw, there seems to be a very similar issue for this model Dell laptops: https://www.dell.com/community/Linux-General/Wi-Fi-WiFi-not-found-after-suspend-sleep/td-p/7186711

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-146-generic 4.4.0-146.172
ProcVersionSignature: Ubuntu 4.4.0-146.172-generic 4.4.177
Uname: Linux 4.4.0-146-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CurrentDesktop: Unity
Date: Wed May 8 21:56:07 2019
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
EcryptfsInUse: Yes
InstallationDate: Installed on 2018-12-13 (146 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
SourcePackage: linux-signed
UpgradeStatus: No upgrade log present (probably fresh install)

[Emmanuel Grumbach (egrumbach)]

Fix is here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1c6bca6d75bca2cc47b5eafb9f7f16e368ffbeca