disk: gpt: verify alternate LBA points to last usable LBA

The gpt command require the GPT backup header at the standard location
at the end of the device. Check the alternate LBA value before reading
the GPT backup header from the last usable LBA of the device.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Stefan Herbrechtsmeier 2021-03-08 16:07:11 +00:00 committed by Tom Rini
parent b935d19066
commit d46933839f

View File

@ -692,6 +692,15 @@ int gpt_verify_headers(struct blk_desc *dev_desc, gpt_header *gpt_head,
/* Free pte before allocating again */
free(*gpt_pte);
/*
* Check that the alternate_lba entry points to the last LBA
*/
if (le64_to_cpu(gpt_head->alternate_lba) != (dev_desc->lba - 1)) {
printf("%s: *** ERROR: Misplaced Backup GPT ***\n",
__func__);
return -1;
}
if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
gpt_head, gpt_pte) != 1) {
printf("%s: *** ERROR: Invalid Backup GPT ***\n",