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Re: [LUG] Grub Problem

 

On 15/08/2020 18:53, Neil wrote:

I am reporting back, with a successful outcome. So, many thanks for your time, help and expertise. (I am not pretending that I understand all that went on, mind). There was no need to mess with the BIOS.
MX is the first distro I have come across with this boot repair 
facility. Perhaps there are others, which I have not noticed. Anyway, it 
has turned out to be very useful in this case. Now I will have a look at 
ventoy.net.
Credit where it's due chief, you're getting good at fixing stuff now. 
Mind you, you do seem to get a lot of practice somehow :]
There are no negative point awarded for this but _if_ you'd looked 
really closely at the apt dist-upgrade output the last time you updated 
the PC there would have been an error printed to console. Not a big one 
(especially considering how critical the error was) but it would have 
said amongst the sea of usual text something like "grub-pc: failed" with 
a warning that the bootloader was NOT reinstalled successfully. That 
would have been your only clue and most people would have most likely 
missed it, including me. Quite probably the warning would have even 
scrolled off the top of your console window and so wouldn't have been 
visible if you had for example run the update and then flipped away to 
something else entirely like a web browser while it finished.
This was originally a major Grub security mistake upstream initially 
(aka "boothole" or CVE-2020-10713) that required an unusually major 
client-side fix (reinstalling and resetting the bootloader). Loads of 
distros did not handle the implementation of that fix in their package 
managers at all well and apparently MX Linux was one of them. Your 
laptop dodged it because it's UEFI and the grub2 package behaves very 
differently there compared to BIOS.
Super nasty bug anyway, surprised nobody else has run into it yet.

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