From: Peter Jones Date: Thu, 28 Feb 2013 01:05:17 +0000 (-0800) Subject: block/partitions/efi.c: ensure that the GPT header is at least the size of the structure. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8b8a6e1881be8d73b7a98f84ccec61e624ec5cac;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git 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 Acked-by: Matt Fleming Cc: Jens Axboe Cc: Stephen Warren Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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;