Quoting: GustyGhostBackports aren't always 100% in my experience but I would be surprised if something as prominent as the Linux kernel could have had a botched backport without anyone noticing. All I do is apt-get -t stretch-backports install linux-image-amd64 but this time, after doing so, such a system cannot be booted. It just hangs at a point where I cannot even drop to terminal. Ouch.

You use nVidia drivers? The bug is there. They fixed it in 390.67-2 (-2 being the patch where they fixed it)

Or try this in your grub config.

GRUB_CMDLINE_LINUX="slab_common.usercopy_fallback=Y"

Then run grub-update.

nvidia-graphics-drivers (390.67-2) unstable; urgency=high

  * Add kmem_cache_create_usercopy.patch from Red Hat, fixing "Bad or missing
    usercopy whitelist? Kernel memory exposure attempt detected from SLUB
    object 'nvidia_stack_cache'" on Linux kernels that have disabled
    CONFIG_HARDENED_USERCOPY_FALLBACK (i.e. linux-image-4.16.0-2-* or newer).
    (Closes: #901919)

 -- Andreas Beckmann <[email protected]>  Thu, 05 Jul 2018 02:01:31 +0200

AMDGPU DC is like fusion power. It's always just 10 years from now! (or in this case, the next kernel version from now!). Anyways I'm tired of waiting so I'm just grabbing the newest kernel I can, buggy or not. Oddly, backporting Debian's 4.16 becomes unbootable on Kabini based systems (and on a Celeron based system) but when I boot that drive on Ryzen hardware it works okay begins strobing the display before reaching any login, setting nomodeset is okay, still gets farther than Kabini though.

EDIT_NOT_EDIT: "backporting" unstable's 4.17 is truly running okay for real™ this time; currently testing various functionalities for stability.

I'm using 4.17.3 in Debian testing now - works just fine with Vega 56. My only issue is some segfault in the Wayland session in KDE when the using DisplayPort.

Quoting: slaapliedje

Quoting: GustyGhostBackports aren't always 100% in my experience but I would be surprised if something as prominent as the Linux kernel could have had a botched backport without anyone noticing. All I do is apt-get -t stretch-backports install linux-image-amd64 but this time, after doing so, such a system cannot be booted. It just hangs at a point where I cannot even drop to terminal. Ouch.

You use nVidia drivers? The bug is there. They fixed it in 390.67-2 (-2 being the patch where they fixed it)

Or try this in your grub config.

GRUB_CMDLINE_LINUX="slab_common.usercopy_fallback=Y"

Then run grub-update.

nvidia-graphics-drivers (390.67-2) unstable; urgency=high

  * Add kmem_cache_create_usercopy.patch from Red Hat, fixing "Bad or missing
    usercopy whitelist? Kernel memory exposure attempt detected from SLUB
    object 'nvidia_stack_cache'" on Linux kernels that have disabled
    CONFIG_HARDENED_USERCOPY_FALLBACK (i.e. linux-image-4.16.0-2-* or newer).
    (Closes: #901919)

 -- Andreas Beckmann <[email protected]>  Thu, 05 Jul 2018 02:01:31 +0200

I've had the same problem myself, but with Debian 10 Buster (testing). The screen-going-blank and then failing to boot any further has been reported as due to Nvidia binary blob driver incompatibilities with the Linux kernel. This happened for me with kernel: linux-image-4.16.0-2

I have been intending to fix the issue properly, but as yet I've "solved" it by going onto my Grub2 menu and selecting the previous kernel: linux-image-4.16.0-1 This one boots up without the problem.

I don't know for sure (because I haven't tried it yet), but THIS command might resolve the problem:
dpkg-reconfigure nvidia-kernel-dkms

https://old.reddit.com/r/debian/comments/8vd0k4/kde_broken_after_update_to_plasmadesktop_451251/e1mfq3z/ This link contains the fix for the boot issue on Nvidia driver 390.48 The 390.67 driver does not have the issue with the updated kernel.

Thanks for all the help, guys. I was able to get some testing done. This is what all the fuss was for.