Answering first to note 5, yes. All the times that kernel 4.4.0-83 crashed, the problem goes away if I boot my previous kernel 4.4.0-81.
kernel 4.4.0-83.106 does not crash during all the boots. Only some times. I could not figure out if they are related to cold/hot boots (in the morning always suceeds, thank goodness), CPU temperature, or any other factor. Answering to note 4, regarding the 4.12.0-041200.201707022031 kernel it appears to solve the problem, but I can't be 100% sure. Using the grub Advanced Ubuntu options, I performed 12 reboots, 6 reboots of each kernel 4.4.0-83.106 and 4.12.0-041200.201707022031 interleaved (boot 4.4.0-83.106, then reboot 4.12.0-041200, then reboot 4.4.0-83.106, etc...) Kernel 4.4.0-83.106 crashed on boot (with the same error) 3 out of 6 times. Kernel 4.12.0-041200 crashed 0 (zero) out of 6 times. Not all reboots took a 5 second power-off interval. (The ones that kernel 4.4.0-83 crashed, did wait a few seconds before booting again). So, the fix looks promising. Meanwhile, I go back to kernel 4.4.0-83 or 4.4.0-81 because I need virtualbox (but I leave 4.12.0-041200 installed for now). For my own record, the procedure I followed to install the 4.12.0-041200 was: wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.12/linux- headers-4.12.0-041200_4.12.0-041200.201707022031_all.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.12/linux- headers-4.12.0-041200-generic_4.12.0-041200.201707022031_amd64.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.12/linux- image-4.12.0-041200-generic_4.12.0-041200.201707022031_amd64.deb sha1sum *.deb # sums looked ok # as root (su -) from now on dpkg -i *.deb # ... # ERROR (dkms apport): kernel package linux-headers-4.12.0-041200-generic is not supported (twice) # ... # lots of W: Possible missing firmware /lib/firmware/nvidia/... But it did boot fine afterwards. (I did not attempt to remove or run virtualbox). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1703091 Title: Kernel panic - not syncing: Fatal exception in interrupt To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1703091/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs