Grub Update trouble [RESOLVED]

[mike acker]

the routine system updater wanted to install a GRUB2 update

I do all the updates so I went ahead with this one

result:

GRUB RESCUE MODE


what on earth do I do with this ?

fortunately it did not destroy the GRUB on the Debian9 disc and I can use that to start the system

[Pjotr]

Best to restore a recent Timeshift snapshot and blacklist this Grub update.

[mike acker]

Best to restore a recent Timeshift snapshot and blacklist this Grub update.

I have a snap from yesterday and I tried a restore from that -- no help
the rescue message identifies CALLOC as the problem --

(P1) ( SDA) .... is Debian-9 : OK
(P3) (SDB) ... is MSFT/W-10 : OK
(P5) (SDD) ... is LMDE/4 -- which boots OK if GRUB is launched from sda or sdb

Maybe I should just re-install the LMDE/4 O/S ? ( keeping the existing partitions )
seems like there a grub fix tool someplace -- I should be able to run it from the Deb-9 system...

Update: there is a boot repair tool in the repos. any experience with this ? I need to take care that it does not further damage things.

[Lbl]

Try disabling secure boot. The GRUB2 update is a security fix, and consequently disables older kernels from booting. A kernel update came about two hours after the GRUB2 update ( probably should have been pushed at the same time). If this fix works, your update manager should have a kernel update waiting for you, update and then you can safely re-enable secure boot. Good luck!

[Pierre]

that 'BootHole' attack impacts Windows and Linux systems using GRUB2 and Secure Boot:
https://www.zdnet.com/article/boothole- ... cure-boot/?

[argentwolf]

This from Debian...

"GRUB2 UEFI SecureBoot vulnerability - 'BootHole'"
https://www.debian.org/security/2020-GR ... ecureBoot/

[mike acker]

yuk

now I don't know what to do or how to help my other people--

I just ran the apt upgrade on this box -- which is Debian-10. The update offered me the option to continue without installing GRUB; I took that option and the system re-boots OK.

Afer a while I'll check the other machine -- which is LMDE-4 ( also Debian-9, or Win-10 ) -- and see if the LMDE-4 has received a kernel update

one of the problems with this update is that it asks "where to install grub ". This response should be "for any bootable disc: there are three in the Research Box: LMDE-4, Debian-9, and Win-10 but it seems like the list presented by the update simply listed all the partitions it found on the five discs that are installed in this system

Right now the LMDE-4 system can only be started using the GRUB program from the Debian-9 or WIN-10 system.

Hopefully I can restart the LMDE-4 and then hopefully it will receive the kernel update and boot properly. we'll see, soon enough.

[mike acker]

This from Debian...

"GRUB2 UEFI SecureBoot vulnerability - 'BootHole'"
https://www.debian.org/security/2020-GR ... ecureBoot/

thanks for this post

it appears to me we need to suspend maintenance until this grubby little problem gets ironed out.

Note:

I'm not sure it's possible to "disable secure boot" ( this is a BIOS option ) -- on a system that is using GPT (GUID) partitioning. AFAIK such system do not have a "Master Boot Record" ( MBR ) ; they have to boot from the UEFI partition. I may be wrong on this.

[nicolaasjan]

Best to restore a recent Timeshift snapshot and blacklist this Grub update.

I was greeted with the infamous "grub rescue" as well...
Fortunately I just made a Timeshift snapshot before applying the grub update
I could restore from a Mint 19.2 Live USB stick.

Code: Select all

uname -a
Linux nico-desktop 4.15.0-112-generic #113-Ubuntu SMP Thu Jul 9 23:41:39 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

How could they make such a terrible mistake!

[EDIT]
Not LMDE here, but Linux Mint 19.3.

[Pjotr]

How could they make such a terrible mistake!

Happens rarely, but it does happen... That's why I always apply this on the machines of digitally handicapped people for whom I am the system administrator:
https://easylinuxtipsproject.blogspot.c ... html#ID3.1
(item 3.1)

[mike acker]

30 JUL 2020

As of this morning I did not find any further updates available for the LMDE-4 system: no kernel update.

I did a new download for the LMDE-4 .iso
The SHA256SUM for the LMDE-4 media remains unchanged.

+

the install media might have an option to re-install GRUB. I might look for this, maybe Friday or Sunday: Only the EVAL system on the ResearchBox is down and that can be booted by using the GRUB on the Deb-9 disc.

what happened on this anyway ? someone forgot to check their pre-reqs ?

/w

[kleinbottle]

Same thing happened with me after the recent grub2 (dummy package update).It landed me at a grub_rescue prompt with some message about CALLOC whatever that means.I run Linux Mint Mate 19.3.Luckily Timeshift came to the rescue.

[zabba]

Same here on Linux Mint 19.3 xfce (GRUB RESCUE MODE, problem with CALLOC). My solution:

1. Reboot using usb live
2. Boot Repair tool
3. Check disk with Gparted (enjoying the moment)

And that's all. Linux mint fine again!

[cosmiclaser]

Beginner here... Can someone give more details on how to solve this ?
When I these steps, I don't understand steps 2 and 3:
1. Reboot using usb live
2. Boot Repair tool
3. Check disk with Gparted (enjoying the moment)

[zabba]

Run program called Boot Repair from Live USB/DVD Linux Mint (my distro is 19.3 xfce legacy). 'If you want' check your disk with Gparted.

https://help.ubuntu.com/community/Boot-Repair

Or follow instructions from 'Pjotr'...

'Best to restore a recent Timeshift snapshot and blacklist this Grub update.'

[mike acker]

I tried the time-shift -- but -- no help

The Boot-Repair is available on my LMDE-4 system from the repos. I could install it and run it,

BUT: I'm not familiar with this program so I'm unwilling to run it with the system discs for the other O/S systems connected. So: I'll have to run it from the install media. I expect it will be available from the Start Menu from the "live" install media.

HOWEVER: I'm going to hold for a couple days: As I understand this there is a co-requisite kernel update that is required in order to boot with the updated version of GRUB2

this whole thing is a dangerous situation: we do not want the GRUB2 update to spread to other systems which might not get the co-requisite updates.

I'm going to hang here and check for updates, probably until Sunday at which time I may simply re-install the LMDE-4 system onto its existing partitions.

[cosmiclaser]

Two related questions here...
1) Is it better to
A) 'Restore a recent Timeshift snapshot and blacklist this Grub update.'
or B) use Boot Repair from the LiveCD.

2) In Boot Repair, do you choose "Recommended Repair" or another option ?

[zabba]

Cosmilaser follow 'Pjotr' recomendation:

'Best to restore a recent Timeshift snapshot and blacklist this Grub update.'

Good luck!

[mrproper]

If you want to repair grub without Boot-Repair the steps are these from a live-cd (for a system installed in /dev/sda1, for other partition or disk change it accordingly):

Code: Select all

mount /dev/sda1 /media/target
mount -t proc proc /media/target/proc/
mount -t sysfs sys /media/target/sys/
mount -o bind /dev /media/target/dev/
chroot /media/target
grub-install /dev/sda

[kleinbottle]

Frankly i'm really pissed off with this update.First you're told that this update is essential to patch a major security hole in grub2 and then the very same update ends up borking your system.What a clusterf@#!k!!! Luckily i run a triple boot system.So my solution was to boot up into PCLinuxOS and run Timeshift from there.