Use gpt_header.sizeof_partition_entry instead of sizeof(gpt_entry) for GPT entry size. According to UEFI 2.7 spec 5.3.1 "GPT overview":, the size of a GUID Partition Entry element is defined in the Size Of Partition Entry field of GPT header. The GPT with entries sized more than sizeof(gpt_entry) is not illegal. OVMF firmware from EDK2 perfectly works with it, see edk2-tianocore source code. Changes since v1: refactoring (extract get_gpt_entry function), fix (&ptes[i] -> pte) Changes since v2: use le32_to_cpu, fix typo, sanity check for sizeof_partition_entry Changes since v3: style fixes Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxx> --- block/partitions/efi.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/block/partitions/efi.c b/block/partitions/efi.c index 39f70d968754..0d10a582b5bc 100644 --- a/block/partitions/efi.c +++ b/block/partitions/efi.c @@ -429,8 +429,8 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba, goto fail; } /* Check that sizeof_partition_entry has the correct value */ - if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { - pr_debug("GUID Partition Entry Size check failed.\n"); + if (le32_to_cpu((*gpt)->sizeof_partition_entry) < sizeof(gpt_entry)) { + pr_debug("GUID Partition Entry Size is too small.\n"); goto fail; } @@ -670,6 +670,12 @@ static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, return 0; } +static gpt_entry *get_gpt_entry(gpt_header *gpt, gpt_entry *ptes, u32 index) +{ + return (gpt_entry *)((u8 *)ptes + + le32_to_cpu(gpt->sizeof_partition_entry) * index); +} + /** * efi_partition(struct parsed_partitions *state) * @state: disk parsed partitions @@ -704,32 +710,35 @@ int efi_partition(struct parsed_partitions *state) pr_debug("GUID Partition Table is valid! Yea!\n"); - for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { + for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && + i < state->limit-1; i++) { + gpt_entry *pte = get_gpt_entry(gpt, ptes, i); struct partition_meta_info *info; unsigned label_count = 0; unsigned label_max; - u64 start = le64_to_cpu(ptes[i].starting_lba); - u64 size = le64_to_cpu(ptes[i].ending_lba) - - le64_to_cpu(ptes[i].starting_lba) + 1ULL; + u64 start = le64_to_cpu(pte->starting_lba); + u64 size = le64_to_cpu(pte->ending_lba) - + le64_to_cpu(pte->starting_lba) + 1ULL; - if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) + if (!is_pte_valid(pte, last_lba(state->bdev))) continue; put_partition(state, i+1, start * ssz, size * ssz); /* If this is a RAID volume, tell md */ - if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) + if (!efi_guidcmp(pte->partition_type_guid, + PARTITION_LINUX_RAID_GUID)) state->parts[i + 1].flags = ADDPART_FLAG_RAID; info = &state->parts[i + 1].info; - efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid); + efi_guid_to_str(&pte->unique_partition_guid, info->uuid); /* Naively convert UTF16-LE to 7 bits. */ label_max = min(ARRAY_SIZE(info->volname) - 1, - ARRAY_SIZE(ptes[i].partition_name)); + ARRAY_SIZE(pte->partition_name)); info->volname[label_max] = 0; while (label_count < label_max) { - u8 c = ptes[i].partition_name[label_count] & 0xff; + u8 c = pte->partition_name[label_count] & 0xff; if (c && !isprint(c)) c = '!'; info->volname[label_count] = c; -- 2.18.0