cryptodisk: Fix incorrect calculation of start sector

Here dev is a grub_cryptodisk_t and dev->offset is offset in sectors of size
native to the cryptodisk device. The sector is correctly transformed into
native grub sector size, but then added to dev->offset which is not
transformed. It would be nice if the type system would help us with this.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Glenn Washburn 2020-09-07 17:27:59 +02:00 committed by Daniel Kiper
parent 3b3ac0c982
commit e1b0992a8d
2 changed files with 11 additions and 7 deletions

View file

@ -757,9 +757,8 @@ grub_cryptodisk_read (grub_disk_t disk, grub_disk_addr_t sector,
size, sector, dev->offset); size, sector, dev->offset);
err = grub_disk_read (dev->source_disk, err = grub_disk_read (dev->source_disk,
(sector << (disk->log_sector_size grub_disk_from_native_sector (disk, sector + dev->offset),
- GRUB_DISK_SECTOR_BITS)) + dev->offset, 0, 0, size << disk->log_sector_size, buf);
size << disk->log_sector_size, buf);
if (err) if (err)
{ {
grub_dprintf ("cryptodisk", "grub_disk_read failed with error %d\n", err); grub_dprintf ("cryptodisk", "grub_disk_read failed with error %d\n", err);
@ -816,12 +815,10 @@ grub_cryptodisk_write (grub_disk_t disk, grub_disk_addr_t sector,
} }
/* Since ->write was called so disk.mod is loaded but be paranoid */ /* Since ->write was called so disk.mod is loaded but be paranoid */
sector = sector + dev->offset;
if (grub_disk_write_weak) if (grub_disk_write_weak)
err = grub_disk_write_weak (dev->source_disk, err = grub_disk_write_weak (dev->source_disk,
(sector << (disk->log_sector_size grub_disk_from_native_sector (disk, sector),
- GRUB_DISK_SECTOR_BITS))
+ dev->offset,
0, size << disk->log_sector_size, tmp); 0, size << disk->log_sector_size, tmp);
else else
err = grub_error (GRUB_ERR_BUG, "disk.mod not loaded"); err = grub_error (GRUB_ERR_BUG, "disk.mod not loaded");

View file

@ -174,6 +174,13 @@ typedef struct grub_disk_memberlist *grub_disk_memberlist_t;
/* Return value of grub_disk_get_size() in case disk size is unknown. */ /* Return value of grub_disk_get_size() in case disk size is unknown. */
#define GRUB_DISK_SIZE_UNKNOWN 0xffffffffffffffffULL #define GRUB_DISK_SIZE_UNKNOWN 0xffffffffffffffffULL
/* Convert to GRUB native disk sized sector from disk sized sector. */
static inline grub_disk_addr_t
grub_disk_from_native_sector (grub_disk_t disk, grub_disk_addr_t sector)
{
return sector << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
}
/* This is called from the memory manager. */ /* This is called from the memory manager. */
void grub_disk_cache_invalidate_all (void); void grub_disk_cache_invalidate_all (void);