[PATCH v2] partitions/efi: Fix partition name parsing in GUID partition entry

From: Nikolai Merinov
Date: Tue Dec 24 2019 - 04:21:52 EST


GUID partition entry defined to have a partition name as 36 UTF-16LE
code units. This means that on big-endian platforms ASCII symbols
would be read with 0xXX00 efi_char16_t character code. In order to
correctly extract ASCII characters from a partition name field we
should be converted from 16LE to CPU architecture.

The problem exists on all big endian platforms.

Signed-off-by: Nikolai Merinov <n.merinov@xxxxxxxxxxxxxxxxxx>

diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index db2fef7dfc47..51287a8a3bea 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -715,7 +715,7 @@ int efi_partition(struct parsed_partitions *state)
ARRAY_SIZE(ptes[i].partition_name));
info->volname[label_max] = 0;
while (label_count < label_max) {
- u8 c = ptes[i].partition_name[label_count] & 0xff;
+ u8 c = le16_to_cpu(ptes[i].partition_name[label_count]) & 0xff;
if (c && !isprint(c))
c = '!';
info->volname[label_count] = c;
diff --git a/block/partitions/efi.h b/block/partitions/efi.h
index 3e8576157575..0b6d5b7be111 100644
--- a/block/partitions/efi.h
+++ b/block/partitions/efi.h
@@ -88,7 +88,7 @@ typedef struct _gpt_entry {
__le64 starting_lba;
__le64 ending_lba;
gpt_entry_attributes attributes;
- efi_char16_t partition_name[72 / sizeof (efi_char16_t)];
+ __le16 partition_name[72 / sizeof (__le16)];
} __packed gpt_entry;

typedef struct _gpt_mbr_record {
--
2.17.1