On Thu, May 16, 2024 at 12:04:21PM GMT, Michael Chang wrote: > On Wed, May 08, 2024 at 05:48:15PM GMT, Daniel Kiper via Grub-devel wrote: > > Adding Marta... > > > > On Mon, May 06, 2024 at 03:18:45PM -0500, Glenn Washburn wrote: > > > From: Rogier <rogier...@gmail.com> > > > > > > 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 lvm.c, > > > when > > > the metadata area wraps around. Apparently, this can start happening at > > > around 220 metadata changes to the VG. > > The number of times to commit a wrap actually depends on the size of the > metadata area, how many LVs and VGs are connected to the PV and > whichever would take part in the size of active raw metadata block > within the area. > > I managed to use the attached shell script to prepare a LVM disk where > the metadata area is in wrapped state. It took about 100 cycles for me.
Hm. In each cycle, two changes (lvcreate/lvremove) are committed. Combined with the initial 30 LVs commit, the total is very close to your 220 metadata changes. Thanks, Michael > With that, I could see the error occurred, and with the patch, the > problem is gone. > > So, Feel free to add my: > > Tested-By: Michael Chang <mch...@suse.com> > > Thanks, > Michael > > > > > > > Fixes: 879c4a834 (lvm: Fix two more potential data-dependent alloc > > > overflows) > > > Fixes: https://savannah.gnu.org/bugs/?61620 > > > > > > Signed-off-by: Rogier <rogier...@gmail.com> > > > Signed-off-by: Glenn Washburn <developm...@efficientek.com> > > > > Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com> > > > > Marta, may I ask you to test this patch? > > > > > --- > > > I have done no testing of this patch. I've only created a suitable patch > > > for review. This seems like a fairly serious issue that might one day bite > > > me, so I think it deserves a review. > > > > > > Glenn > > > --- > > > 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 794248540cd3..8535d5a5863a 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; > > > > Daniel > > > > _______________________________________________ > > Grub-devel mailing list > > Grub-devel@gnu.org > > https://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
