partitions: read whole sector with EFI GPT header
The size of EFI GPT header is not static, but whole sector is
allocated for the header. The HeaderSize field must be greater
than 92 (= sizeof(struct gpt_header) and must be less than or
equal to the logical block size.
It means we have to read whole sector with the header, because the
header crc32 checksum is calculated according to HeaderSize.
For more details see UEFI standard (version 2.3, May 2009):
- 5.3.1 GUID Format overview, page 93
- Table 13. GUID Partition Table Header, page 96
Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c
index 80eeff5..49cfd5f 100644
--- a/fs/partitions/efi.c
+++ b/fs/partitions/efi.c
@@ -262,15 +262,16 @@
alloc_read_gpt_header(struct block_device *bdev, u64 lba)
{
gpt_header *gpt;
+ unsigned ssz = bdev_logical_block_size(bdev);
+
if (!bdev)
return NULL;
- gpt = kzalloc(sizeof (gpt_header), GFP_KERNEL);
+ gpt = kzalloc(ssz, GFP_KERNEL);
if (!gpt)
return NULL;
- if (read_lba(bdev, lba, (u8 *) gpt,
- sizeof (gpt_header)) < sizeof (gpt_header)) {
+ if (read_lba(bdev, lba, (u8 *) gpt, ssz) < ssz) {
kfree(gpt);
gpt=NULL;
return NULL;