El Wednesday 07 May 2008 10:03:08 Robert Millan escribió: > On Tue, May 06, 2008 at 11:02:20PM -0430, Isaac M. Marcos wrote: > > > > Program received signal SIGSEGV, Segmentation fault. > > > > 0x0000000000421b7c in grub_lvm_scan_device (name=0x638210 "hd1,5") at > > > > /home/immf/grub2-1.96+20080429/disk/lvm.c:305 305 while (*q != > > > > ' ') > > > > > > Please try: > > > > > > print q > > > print metadatabuf > > > print rlocn->offset > > > > (gdb) run -t device / > > Starting program: /usr/sbin/grub-probe -t device / > > > > Program received signal SIGSEGV, Segmentation fault. > > 0x0000000000421b7c in grub_lvm_scan_device (name=0x638210 "hd1,5") > > at /home/immf/grub2-1.96+20080429/disk/lvm.c:305 > > 305 while (*q != ' ') > > (gdb) print q > > $1 = 0x78b000 <Address 0x78b000 out of bounds> > > (gdb) print metadatabuf > > $2 = 0x73ba00 "�N\203\220 LVM2 x[5A%r0N*>\001" # the ? symbol > > is a 0x00 > > (gdb) print rlocn->offset > > $3 = 92672 > > Looks like rlocn->offset is messed up. Maybe it's mdah->raw_locns fault, > or maybe on its own ground. > > In either case, I'm not sure what we're supposed to do about it. Appliing > an heuristic to rlocn->offset isn't good... > > Please could you bring this to upstream ([EMAIL PROTECTED])? Maybe > someone with a better understanding of this code can help.
> 2008/5/16 Pavel Roskin: > > > (gdb) print mda_size > > $1 = 192512 > > OK, we have something interesting here. mda_size is 192512 (0x2f000). > rlocn->offset is 92672 (0x16a00). But (q - metadatabuf) is 325120 > (0x4f600). So, the initial value of q was within the buffer, but the > value that caused the segfault was outside the buffer. > > It means that GRUB could not find any space character in the buffer and > kept scanning until it hit unallocated space. I believe it's not valid > LVM metadata. > > > # pvck /dev/sda6 > > Device /dev/sda6 not found (or ignored by filtering). > > So, it's not a LVM physical volume. > > > /dev/sda6 3397 6561 25422831 fd Linux raid autodetect > > It's a RAID partition. I guess RAID partitions have a different layout. > > The fix would be to reject RAID partitions in grub_lvm_scan_device(). > The only validity check in that function is presence of the LVM label in > the first 4 sectors. Perhaps additional checks are needed. Looks like the LVM checking needs to include some functions from "pvck", or include a check for RAID disks before going to LVM. -- Isaac M. Marcos GPG key 0xC9045C1B 5633 ECAF 44B1 8A5D 9371 DCDA 4620 A016 C904 5C1B The only place success comes before work is in the dictionary. VINCE LOMBARDI
signature.asc
Description: This is a digitally signed message part.
