fat: fix FAT sector offsets overflow on large FAT partitions
This patch fixes several issues where sector offsets can overflow due
to being limited to 16-bits. The cases where an overflow can happen
when accessing large FAT32 partitions are:
- length of FAT in sectors
- start sector of root directory
- the sector of the first cluster
These issues were observed when reading files from a 64GB FAT32
filesystem.
Signed-off-by: Aaron Williams <aaron.williams@caviumnetworks.com>
Tested-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/include/fat.h b/include/fat.h
index 4c92442..f1b4a0d 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -178,12 +178,12 @@
typedef struct {
__u8 *fatbuf; /* Current FAT buffer */
int fatsize; /* Size of FAT in bits */
- __u16 fatlength; /* Length of FAT in sectors */
+ __u32 fatlength; /* Length of FAT in sectors */
__u16 fat_sect; /* Starting sector of the FAT */
- __u16 rootdir_sect; /* Start sector of root directory */
+ __u32 rootdir_sect; /* Start sector of root directory */
__u16 sect_size; /* Size of sectors in bytes */
__u16 clust_size; /* Size of clusters in sectors */
- short data_begin; /* The sector of the first cluster, can be negative */
+ int data_begin; /* The sector of the first cluster, can be negative */
int fatbufnum; /* Used by get_fatent, init to -1 */
} fsdata;