partitions/efi: Fix partition name parsing in GUID partition entry

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.

[ mingo: Minor edits. ]

Fixes: eec7ecfede ("genhd, efi: add efi partition metadata to hd_structs")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200308080859.21568-29-ardb@kernel.org
Link: https://lore.kernel.org/r/797777312.1324734.1582544319435.JavaMail.zimbra@inango-systems.com/
This commit is contained in:
Nikolai Merinov 2020-03-08 09:08:59 +01:00 committed by Ingo Molnar
parent 0347d8c28c
commit d5528d5e91
2 changed files with 27 additions and 10 deletions

View File

@ -656,6 +656,31 @@ static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
return 0;
}
/**
* utf16_le_to_7bit(): Naively converts a UTF-16LE string to 7-bit ASCII characters
* @in: input UTF-16LE string
* @size: size of the input string
* @out: output string ptr, should be capable to store @size+1 characters
*
* Description: Converts @size UTF16-LE symbols from @in string to 7-bit
* ASCII characters and stores them to @out. Adds trailing zero to @out array.
*/
static void utf16_le_to_7bit(const __le16 *in, unsigned int size, u8 *out)
{
unsigned int i = 0;
out[size] = 0;
while (i < size) {
u8 c = le16_to_cpu(in[i]) & 0xff;
if (c && !isprint(c))
c = '!';
out[i] = c;
i++;
}
}
/**
* efi_partition(struct parsed_partitions *state)
* @state: disk parsed partitions
@ -692,7 +717,6 @@ int efi_partition(struct parsed_partitions *state)
for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; 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) -
@ -713,14 +737,7 @@ int efi_partition(struct parsed_partitions *state)
/* Naively convert UTF16-LE to 7 bits. */
label_max = min(ARRAY_SIZE(info->volname) - 1,
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;
if (c && !isprint(c))
c = '!';
info->volname[label_count] = c;
label_count++;
}
utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname);
state->parts[i + 1].has_info = true;
}
kfree(ptes);

View File

@ -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 {