Dear maintainer, I have also run into this bug, in the same version of grub (2.02+dfsg1-20+deb10u4).
As *any* change to the LVM configuration can trigger the bug, rendering the system unbootable, this is a ticking bomb for users of LVM. IMO the severity of this bug should be increased to critical. I did some investigation, and the cause is an incorrect computation of mda_end when the metadata area wraps around. The following patch fixes the problem: --------------------------------------------------- Index: grub2-2.02+dfsg1/grub-core/disk/lvm.c =================================================================== --- grub2-2.02+dfsg1.orig/grub-core/disk/lvm.c +++ grub2-2.02+dfsg1/grub-core/disk/lvm.c @@ -253,7 +253,7 @@ error_parsing_metadata: p = q = (char *)ptr; - if (grub_add ((grub_size_t)metadatabuf, (grub_size_t)mda_size, &ptr)) + if (grub_add (ptr, (grub_size_t)grub_le_to_cpu64 (rlocn->size), &ptr)) goto error_parsing_metadata; mda_end = (char *)ptr; ---------------------------------------------------- I checked the sources of grub2-2.04 in bullseye, and the code in question looks exactly the same, so this same bug is also present in bullseye and testing. Kind regards, Rogier.