Commit 8b8a6e18 authored by Peter Jones's avatar Peter Jones Committed by Linus Torvalds
Browse files

block/partitions/efi.c: ensure that the GPT header is at least the size of the structure.



UEFI 2.3.1D will include a change to the spec language mandating that a
GPT header must be greater than *or equal to* the size of the defined
structure.  While verifying that this would work on Linux, I discovered
that we're not actually checking the minimum bound at all.

The result of this is that when we verify the checksum, it's possible that
on a malformed header (with header_size of 0), we won't actually verify
any data.

[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: default avatarPeter Jones <pjones@redhat.com>
Acked-by: default avatarMatt Fleming <matt.fleming@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 86ee8ba6
......@@ -310,15 +310,23 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
goto fail;
}
/* Check the GUID Partition Table header size */
/* Check the GUID Partition Table header size is too big */
if (le32_to_cpu((*gpt)->header_size) >
bdev_logical_block_size(state->bdev)) {
pr_debug("GUID Partition Table Header size is wrong: %u > %u\n",
pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
le32_to_cpu((*gpt)->header_size),
bdev_logical_block_size(state->bdev));
goto fail;
}
/* Check the GUID Partition Table header size is too small */
if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
le32_to_cpu((*gpt)->header_size),
sizeof(gpt_header));
goto fail;
}
/* Check the GUID Partition Table CRC */
origcrc = le32_to_cpu((*gpt)->header_crc32);
(*gpt)->header_crc32 = 0;
......
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