[parted-devel] [PATCH 3/9] Fix gpt_read to read all of the partition entries correctly.

[Joel Granados Moreno]

From: Matthew S. Harris <mharris312 at gmail.com>

* libparted/labels/gpt.c (gpt_read): Use the SizeOfPartitionEntry
field value when reading the partition entries rather than assuming
that the entries are the same size as our struct.

* libparted/labels/gpt.c (gpt_read): When reading the partition
entries, round up, not down, the number of sectors to read.

* libparted/labels/gpt.c (_header_is_valid): Check that the
  SizeOfPartitionEntry is sane.
---
 libparted/labels/gpt.c |   29 ++++++++++++++++++++++-------
 1 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c
index 89e46fc..4597346 100644
--- a/libparted/labels/gpt.c
+++ b/libparted/labels/gpt.c
@@ -38,6 +38,7 @@
 #include <unistd.h>
 #include <uuid/uuid.h>
 #include <stdbool.h>
+#include "xalloc.h"
 
 #if ENABLE_NLS
 #  include <libintl.h>
@@ -603,6 +604,14 @@ _header_is_valid (const PedDevice* dev, GuidPartitionTableHeader_t* gpt)
 	    || PED_LE32_TO_CPU (gpt->HeaderSize) > dev->sector_size)
 		return 0;
 
+	/*
+	 * the SizeOfPartitionEntry must be a multiple of 8 and
+	 * greater than the size of the PartitionEntry structure.
+	 */
+	uint32_t sope = gpt->SizeOfPartitionEntry;
+	if (sope % 8 != 0 || sope < sizeof(GuidPartitionEntry_t) )
+		return 0;
+
 	origcrc = gpt->HeaderCRC32;
 	gpt->HeaderCRC32 = 0;
 	crc = pth_crc32 (dev, gpt);
@@ -807,8 +816,8 @@ gpt_read (PedDisk * disk)
 {
 	GPTDiskData *gpt_disk_data = disk->disk_specific;
 	GuidPartitionTableHeader_t* gpt;
-	GuidPartitionEntry_t* ptes;
-	int ptes_size;
+	void* ptes;
+	int ptes_sectors;
 	int i;
 #ifndef DISCOVER_ONLY
 	int write_back = 0;
@@ -902,22 +911,28 @@ gpt_read (PedDisk * disk)
 	if (!_parse_header (disk, gpt, &write_back))
 		goto error_free_gpt;
 
+	ptes_sectors = ped_div_round_up(gpt->SizeOfPartitionEntry *
+		gpt_disk_data->entry_count, disk->dev->sector_size);
+
+	if (xalloc_oversized (ptes_sectors, disk->dev->sector_size))
+		goto error_free_gpt;
+	ptes = ped_malloc (ptes_sectors * disk->dev->sector_size);
 
-	ptes_size = sizeof (GuidPartitionEntry_t) * gpt_disk_data->entry_count;
-	ptes = (GuidPartitionEntry_t*) ped_malloc (ptes_size);
 	if (!ped_device_read (disk->dev, ptes,
 			      PED_LE64_TO_CPU(gpt->PartitionEntryLBA),
-			      ptes_size / disk->dev->sector_size))
+			      ptes_sectors))
 		goto error_free_ptes;
 
 	for (i = 0; i < gpt_disk_data->entry_count; i++) {
+		GuidPartitionEntry_t* pte = (GuidPartitionEntry_t*) (ptes +
+			i * gpt->SizeOfPartitionEntry);
 		PedPartition* part;
 		PedConstraint* constraint_exact;
 
-		if (!guid_cmp (ptes[i].PartitionTypeGuid, UNUSED_ENTRY_GUID))
+		if (!guid_cmp (pte->PartitionTypeGuid, UNUSED_ENTRY_GUID))
 			continue;
 
-		part = _parse_part_entry (disk, &ptes[i]);
+		part = _parse_part_entry (disk, pte);
 		if (!part)
 			goto error_delete_all;
 
-- 
1.6.0.6