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msdos: Fix overflow in converting partition start and length into 512B blocks

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When booting from NVME SSD with 4k sector size, it fails with the message.

error: attempt to read or write outside of partition.

This patch fixes the problem by fixing overflow in converting partition start
and length into 512B blocks.

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Michael Chang 2018-09-13 16:08:20 +08:00 committed by Vincent Batts
parent d3b1d4c188
commit 5a0a15c05b
1 changed files with 6 additions and 6 deletions
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12
grub-core/partmap/msdos.c
View file

@ -175,9 +175,9 @@ grub_partition_msdos_iterate (grub_disk_t disk,
e = mbr.entries + p.index;
p.start = p.offset
+ (grub_le_to_cpu32 (e->start)
+ ((grub_disk_addr_t)grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) - delta;
p.len = grub_le_to_cpu32 (e->length)
p.len = (grub_uint64_t)grub_le_to_cpu32 (e->length)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
p.msdostype = e->type;
@ -210,7 +210,7 @@ grub_partition_msdos_iterate (grub_disk_t disk,
if (grub_msdos_partition_is_extended (e->type))
{
p.offset = ext_offset
+ (grub_le_to_cpu32 (e->start)
+ ((grub_disk_addr_t)grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
if (! ext_offset)
ext_offset = p.offset;
@ -294,9 +294,9 @@ pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
if (!grub_msdos_partition_is_empty (e->type)
&& end > offset
+ (grub_le_to_cpu32 (e->start)
+ ((grub_disk_addr_t)grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)))
end = offset + (grub_le_to_cpu32 (e->start)
end = offset + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
/* If this is a GPT partition, this MBR is just a dummy. */
@ -312,7 +312,7 @@ pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
if (grub_msdos_partition_is_extended (e->type))
{
offset = ext_offset
+ (grub_le_to_cpu32 (e->start)
+ ((grub_disk_addr_t)grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
if (! ext_offset)
ext_offset = offset;