From: Rogier Date: Mon, 19 Jun 2023 17:23:25 +0200 Subject: fix renamed LV detection MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Origin: other Bug: https://savannah.gnu.org/bugs/index.php?61620 Bug-Debian: https://bugs.debian.org/987008 Forwarded: https://savannah.gnu.org/bugs/index.php?61620 Reviewed-By: Antoine Beaupré Last-Update: 2023-02-25 It looks like the detection of the LVM logical volumes fails in certain edge conditions. In particular, it was reported that renaming an LV will make grub fail to boot from the system as it cannot properly detect it anymore. . I have looked at the code surrounding the patch and cannot claim to understand the entire function here, as it is huge and quite cryptic. But it seems sane: the `ptr` we're inspecting here starts at the `rlocn->offset`, but we were adding `mda_size` to the (somewhat) unrelated metadatabuf instead. Now we're marking the `mda_end` correctly, based on the rlocn->offsite and ->size. . I have not tested this myself as the test setup is quite involved, but it seems others (e.g. "Hoyer, David" ) have tested the patch and confirmed it worked. --- grub-core/disk/lvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/grub-core/disk/lvm.c b/grub-core/disk/lvm.c index 7942485..8535d5a 100644 --- a/grub-core/disk/lvm.c +++ b/grub-core/disk/lvm.c @@ -290,7 +290,7 @@ grub_lvm_detect (grub_disk_t disk, 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;