From f456add5f4171b27a1f8aca98e02c14e123bbd59 Mon Sep 17 00:00:00 2001 From: Rogier Date: Mon, 6 May 2024 15:18:45 -0500 Subject: disk/lvm: GRUB fails to detect LVM volumes due to an incorrect computation of mda_end When handling a regular LVM volume, GRUB can fail with the message: error: disk `lvmid/******-****-****-****-****-****-****/******-****-****-****-****-****-******' not found. If the condition which triggers this exists, grub-probe will report the error mentioned above. Similarly, the GRUB boot code will fail to detect LVM volumes, resulting in a failure to boot off of LVM disks/partitions. The condition can be created on any LVM VG by an LVM configuration change, so any system with /boot on LVM can become unbootable at "any" time (after any LVM configuration change). The problem is caused by an incorrect computation of mda_end in disk/lvm.c, when the metadata area wraps around. Apparently, this can start happening at around 220 metadata changes to the VG. Fixes: 879c4a834 (lvm: Fix two more potential data-dependent alloc overflows) Fixes: https://savannah.gnu.org/bugs/?61620 Signed-off-by: Rogier Signed-off-by: Glenn Washburn Reviewed-by: Daniel Kiper Tested-By: Michael Chang --- 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..0c32c95 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; -- cgit v1.1