From d5528d5e91041e68e8eab9792ce627705a0ed273 Mon Sep 17 00:00:00 2001 From: Nikolai Merinov Date: Sun, 8 Mar 2020 09:08:59 +0100 Subject: 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: eec7ecfede74 ("genhd, efi: add efi partition metadata to hd_structs") Reviewed-by: Christoph Hellwig Signed-off-by: Nikolai Merinov Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar 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/ --- block/partitions/efi.c | 35 ++++++++++++++++++++++++++--------- block/partitions/efi.h | 2 +- 2 files changed, 27 insertions(+), 10 deletions(-) (limited to 'block') diff --git a/block/partitions/efi.c b/block/partitions/efi.c index db2fef7dfc47..b64bfdd4326c 100644 --- a/block/partitions/efi.c +++ b/block/partitions/efi.c @@ -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); diff --git a/block/partitions/efi.h b/block/partitions/efi.h index 3e8576157575..5fc62fd8d9a9 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 { -- cgit v1.2.3