Re: EFI stub: WARNING: Failed to measure data for event 1: 0x800000000000000b

["Ard Biesheuvel" <ardb@kernel.org>]

Hello Hans,

On Sat, 4 Apr 2026, at 12:54, Hans Schou wrote:
> Hi Ard
>
> This message has start showing for 3 seconds when booting:
> EFI stub: WARNING: Failed to measure data for event 1: 0x800000000000000b
>

This is a harmless warning from the TPM code in your BIOS.

> Afterwards my Linux Mint boots up normally.
>
> Linux p52 6.8.0-107-generic #107-Ubuntu SMP PREEMPT_DYNAMIC Fri Mar 13 
> 19:51:50 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux
>
> GRUB 2.12
>
> This warning occurs only in several different events.
> It can be eliminated in different work arounds:
> 1. Having too many kernels installed. 19 is too many. 4 is few. 
> Solution: Remove some old kernels.
> 2. Enable/Disable secure boot in BIOS (if posssible)
> 3. Having Linux/Windows dual boot. Work around: add 
> "CONFIG_EFI_HANDOVER_PROTOCOL=N EFI_STUB=N" to 
> GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub. 
>
> Only "1." is my own experience.
>

3. seems implausible to me: putting those strings on the command line has no effect, those are build options that must be taken into account while compiling the kernel.


> It seems like this situation happens as a combination of GRUB and the 
> kernel.
> The kernel should not be able to see I have more than 4 kernel 
> installed, as at the time of reporting the warning, one of my the 
> kernels are already about to boot.
> So it could be GRUB which gives some extra parameters to the kernel 
> when booting. How else could the kernel know there are "too many" 
> kernels installed? In that case the bug is in GRUB and the kernel is 
> just reporting it.
>
> By searching internet I found:
> * First seen year 2023 (kernel version not reported)
> * OS reported used: Mint, SuSE, Ubuntu, Ubuntu MATE, Kubuntu
>
> If it's due to GRUB, I apologize for the inconvenience.

You can just ignore this warning. I wouldn't recommend turning off secure boot just for this reason.