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gpt: fix partition table indexing and validation

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Portions of the code attempted to handle the fact that GPT entries on
disk may be larger than the currently defined struct while others
assumed the data could be indexed by the struct size directly. This
never came up because no utility uses a size larger than 128 bytes but
for the sake of safety we need to do this by the spec.
This commit is contained in:
Michael Marineau 2016-08-24 16:14:20 -07:00
parent 87dfbf34c4
commit bf127238ee
4 changed files with 176 additions and 12 deletions
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120
tests/gpt_unit_test.c
View file

@ -40,6 +40,13 @@
/* from gnulib */
#include <verify.h>
/* Confirm that the GPT structures conform to the sizes in the spec:
* The header size "must be greater than or equal to 92 and must be less
* than or equal to the logical block size."
* The partition entry size must be "a value of 128*(2^n) where n is an
* integer greater than or equal to zero (e.g., 128, 256, 512, etc.)." */
verify (sizeof (struct grub_gpt_header) == 92);
verify (sizeof (struct grub_gpt_partentry) == 128);
/* GPT section sizes. */
#define HEADER_SIZE (sizeof (struct grub_gpt_header))
@ -537,6 +544,113 @@ repair_test (void)
close_disk (&data);
}
static void
iterate_partitions_test (void)
{
struct test_data data;
struct grub_gpt_partentry *p;
grub_gpt_t gpt;
grub_uint32_t n;
open_disk (&data);
gpt = read_disk (&data);
for (n = 0; (p = grub_gpt_get_partentry (gpt, n)) != NULL; n++)
grub_test_assert (memcmp (p, &example_entries[n], sizeof (*p)) == 0,
"unexpected partition %d data", n);
grub_test_assert (n == TABLE_ENTRIES, "unexpected partition limit: %d", n);
grub_gpt_free (gpt);
close_disk (&data);
}
static void
large_partitions_test (void)
{
struct test_data data;
struct grub_gpt_partentry *p;
grub_gpt_t gpt;
grub_uint32_t n;
open_disk (&data);
/* Double the entry size, cut the number of entries in half. */
data.raw->primary_header.maxpart =
data.raw->backup_header.maxpart =
grub_cpu_to_le32_compile_time (TABLE_ENTRIES/2);
data.raw->primary_header.partentry_size =
data.raw->backup_header.partentry_size =
grub_cpu_to_le32_compile_time (ENTRY_SIZE*2);
data.raw->primary_header.partentry_crc32 =
data.raw->backup_header.partentry_crc32 =
grub_cpu_to_le32_compile_time (0xf2c45af8);
data.raw->primary_header.crc32 = grub_cpu_to_le32_compile_time (0xde00cc8f);
data.raw->backup_header.crc32 = grub_cpu_to_le32_compile_time (0x6d72e284);
memset (&data.raw->primary_entries, 0,
sizeof (data.raw->primary_entries));
for (n = 0; n < TABLE_ENTRIES/2; n++)
memcpy (&data.raw->primary_entries[n*2], &example_entries[n],
sizeof (data.raw->primary_entries[0]));
memcpy (&data.raw->backup_entries, &data.raw->primary_entries,
sizeof (data.raw->backup_entries));
sync_disk(&data);
gpt = read_disk (&data);
for (n = 0; (p = grub_gpt_get_partentry (gpt, n)) != NULL; n++)
grub_test_assert (memcmp (p, &example_entries[n], sizeof (*p)) == 0,
"unexpected partition %d data", n);
grub_test_assert (n == TABLE_ENTRIES/2, "unexpected partition limit: %d", n);
grub_gpt_free (gpt);
/* Editing memory beyond the entry structure should still change the crc. */
data.raw->primary_entries[1].attrib = 0xff;
sync_disk(&data);
gpt = read_disk (&data);
grub_test_assert (gpt->status == (GRUB_GPT_PROTECTIVE_MBR |
GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID),
"unexpected status: 0x%02x", gpt->status);
grub_gpt_free (gpt);
close_disk (&data);
}
static void
invalid_partsize_test (void)
{
struct grub_gpt_header header = {
.magic = GRUB_GPT_HEADER_MAGIC,
.version = GRUB_GPT_HEADER_VERSION,
.headersize = sizeof (struct grub_gpt_header),
.crc32 = grub_cpu_to_le32_compile_time (0x1ff2a054),
.header_lba = grub_cpu_to_le64_compile_time (PRIMARY_HEADER_SECTOR),
.alternate_lba = grub_cpu_to_le64_compile_time (BACKUP_HEADER_SECTOR),
.start = grub_cpu_to_le64_compile_time (DATA_START_SECTOR),
.end = grub_cpu_to_le64_compile_time (DATA_END_SECTOR),
.guid = GRUB_GPT_GUID_INIT(0x69c131ad, 0x67d6, 0x46c6,
0x93, 0xc4, 0x12, 0x4c, 0x75, 0x52, 0x56, 0xac),
.partitions = grub_cpu_to_le64_compile_time (PRIMARY_TABLE_SECTOR),
.maxpart = grub_cpu_to_le32_compile_time (TABLE_ENTRIES),
/* Triple the entry size, which is not valid. */
.partentry_size = grub_cpu_to_le32_compile_time (ENTRY_SIZE*3),
.partentry_crc32 = grub_cpu_to_le32_compile_time (0x074e052c),
};
grub_gpt_header_check(&header, GRUB_DISK_SECTOR_BITS);
grub_test_assert (grub_errno == GRUB_ERR_BAD_PART_TABLE,
"unexpected error: %s", grub_errmsg);
grub_test_assert (strcmp(grub_errmsg, "invalid GPT entry size") == 0,
"unexpected error: %s", grub_errmsg);
grub_errno = GRUB_ERR_NONE;
}
static void
search_part_label_test (void)
{
@ -657,6 +771,9 @@ grub_unit_test_init (void)
grub_test_register ("gpt_read_invalid_test", read_invalid_entries_test);
grub_test_register ("gpt_read_fallback_test", read_fallback_test);
grub_test_register ("gpt_repair_test", repair_test);
grub_test_register ("gpt_iterate_partitions_test", iterate_partitions_test);
grub_test_register ("gpt_large_partitions_test", large_partitions_test);
grub_test_register ("gpt_invalid_partsize_test", invalid_partsize_test);
grub_test_register ("gpt_search_part_label_test", search_part_label_test);
grub_test_register ("gpt_search_uuid_test", search_part_uuid_test);
grub_test_register ("gpt_search_disk_uuid_test", search_disk_uuid_test);
@ -671,6 +788,9 @@ grub_unit_test_fini (void)
grub_test_unregister ("gpt_read_invalid_test");
grub_test_unregister ("gpt_read_fallback_test");
grub_test_unregister ("gpt_repair_test");
grub_test_unregister ("gpt_iterate_partitions_test");
grub_test_unregister ("gpt_large_partitions_test");
grub_test_unregister ("gpt_invalid_partsize_test");
grub_test_unregister ("gpt_search_part_label_test");
grub_test_unregister ("gpt_search_part_uuid_test");
grub_test_unregister ("gpt_search_disk_uuid_test");