From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756546Ab0C3XMi (ORCPT ); Tue, 30 Mar 2010 19:12:38 -0400 Received: from kroah.org ([198.145.64.141]:48960 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756469Ab0C3XM3 (ORCPT ); Tue, 30 Mar 2010 19:12:29 -0400 X-Mailbox-Line: From linux@linux.site Tue Mar 30 15:58:34 2010 Message-Id: <20100330225833.612743417@linux.site> User-Agent: quilt/0.47-14.9 Date: Tue, 30 Mar 2010 15:57:43 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Karel Zak , Jens Axboe , Greg Kroah-Hartman Subject: [41/89] partitions: read whole sector with EFI GPT header In-Reply-To: <20100330230520.GA28779@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Karel Zak commit 87038c2d5bda2418fda8b1456a0ae81cc3ff5bd8 upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/partitions/efi.c | 7 ++++--- fs/partitions/efi.h | 8 ++++++-- 2 files changed, 10 insertions(+), 5 deletions(-) --- a/fs/partitions/efi.c +++ b/fs/partitions/efi.c @@ -257,15 +257,16 @@ static gpt_header * 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; --- a/fs/partitions/efi.h +++ b/fs/partitions/efi.h @@ -37,7 +37,6 @@ #define EFI_PMBR_OSTYPE_EFI 0xEF #define EFI_PMBR_OSTYPE_EFI_GPT 0xEE -#define GPT_BLOCK_SIZE 512 #define GPT_HEADER_SIGNATURE 0x5452415020494645ULL #define GPT_HEADER_REVISION_V1 0x00010000 #define GPT_PRIMARY_PARTITION_TABLE_LBA 1 @@ -79,7 +78,12 @@ typedef struct _gpt_header { __le32 num_partition_entries; __le32 sizeof_partition_entry; __le32 partition_entry_array_crc32; - u8 reserved2[GPT_BLOCK_SIZE - 92]; + + /* The rest of the logical block is reserved by UEFI and must be zero. + * EFI standard handles this by: + * + * uint8_t reserved2[ BlockSize - 92 ]; + */ } __attribute__ ((packed)) gpt_header; typedef struct _gpt_entry_attributes {