Update-Grub doesn't work

[GBit]

Code: Select all

Killed (core dumped)
Killed (core dumped)
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.8.6grsec1.0-grsec
Found initrd image: /boot/initrd.img-3.8.6grsec1.0-grsec
Killed (core dumped)
Killed (core dumped)
Killed (core dumped)
Killed (core dumped)
Found linux image: /boot/vmlinuz-3.8.0-18-generic
Found initrd image: /boot/initrd.img-3.8.0-18-generic
Killed (core dumped)
Killed (core dumped)
Found linux image: /boot/vmlinuz-3.8.0-17-generic
Found initrd image: /boot/initrd.img-3.8.0-17-generic
Killed (core dumped)
Killed (core dumped)
Killed (core dumped)
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 8 (loader) on /dev/sda1
Killed (core dumped)
Killed (core dumped)
Killed (core dumped)
Syntax errors are detected in generated GRUB config file.
Ensure that there are no errors in /etc/default/grub
and /etc/grub.d/* files or please file a bug report with
/boot/grub/grub.cfg.new file attached.done

I can't install a new kernel without being able to update-grub. I'm having an issue with the grsec kernel and need to temporarily boot into another kernel... but I'm unable to.

If you think think of a way for me to be able to boot into that 3.8.0 kernel let me know. This update-grub issue only happens on grsec kernels.

[PaX Team]

did you get any kernel messages about the kill? what's your grsec config? did this work before?

[GBit]

It has been broken on Grsecurity since I first started using it, probably around 3.2.

I only get what's shown there, though there may be a log with more details that I can get you in about an hour.

It's never been an issue, but as I accidentally removed a vanilla kernel I'm now unable to update grub, which has proved problematic.

config can be found here: http://pastebin.com/f4245sM8

[PaX Team]

interesting, my initial guess was that you had MPROTECT but not EMUTRAMP which is a known combination to trip up grub's use of nested function trampolines (unless grub's marked by paxctl), but you have neither, so that shouldn't be the cause. now it's all the more important to get any kernel logs this may have generated. also since you have coredumps, you should load them into gdb and issue the usual commands (bt, info reg, x/8i $pc, etc).

[GBit]

Having graphics issues, so this is a bit difficult, but here's a portion of my kern.log.

http://pastebin.com/iTBvVc9D

I also have no idea how to actually use coredumps. I know what they are, and I've heard how to use them briefly from a professor, and have never touched them.

[PaX Team]

ok, this is actually the gcc nested function trampoline problem but then it should have failed on earlier kernels as well with your config. in any case, what you can do is either enable EMUTRAMP (in the kernel and on the grub binaries) or disable PAGEEXEC on the grub binaries.

[GBit]

Hm, alright.

Thank you.

[Stephane]

I had the same problem fixed like that :
paxctl -Cpms /usr/sbin/grub-probe
paxctl -Cpms /usr/bin/grub-mount
paxctl -Cpms /usr/bin/grub-script-check