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authorPeter Jones <pjones@redhat.com>2013-02-27 17:05:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-27 19:10:21 -0800
commit8b8a6e1881be8d73b7a98f84ccec61e624ec5cac (patch)
tree4e5e883aeee2ee9371b97e52a053d07c24939f2d
parent86ee8ba64daf5e09a71e4c216f81fae8d1c937f3 (diff)
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: Peter Jones <pjones@redhat.com> Acked-by: Matt Fleming <matt.fleming@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--block/partitions/efi.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index b62fb88b8711..ff5804e2f1d2 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -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;