This modifies most of the places we do some form of:
X = malloc(Y * Z);
to use calloc(Y, Z) instead.
Among other issues, this fixes:
- allocation of integer overflow in grub_png_decode_image_header()
reported by Chris Coulson,
- allocation of integer overflow in luks_recover_key()
reported by Chris Coulson,
- allocation of integer overflow in grub_lvm_detect()
reported by Chris Coulson.
Fixes: CVE-2020-14308
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
GRUB keeps partition offset and size in units of 512B sectors. Media paths
are defined in terms of LBA which are presumed to match HDD sector size.
This is probably cosmetic (EFI requires that partition is searched by GUID)
and still incorrect if GPT was created using different logical block size.
But current code is obviously wrong and new has better chances to be correct.
Fix potential crash caused by signed vs. unsigned comparison. Negative
length compares as very large unsigned number causing subsequent NULL access.
Make exhaustive search for all BootNNNN variables to find one matching
requested efi_distributor.
