exfat: fix overflow issue in exfat_cluster_to_sector()

An overflow issue can occur while calculating sector in
exfat_cluster_to_sector(). It needs to cast clus's type to sector_t
before left shifting.

Fixes: 1acf1a564b ("exfat: add in-memory and on-disk structures and headers")
Cc: stable@vger.kernel.org # v5.7
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
This commit is contained in:
Namjae Jeon 2020-07-03 11:16:32 +09:00
parent ba47d845d7
commit 43946b7049

View File

@ -371,7 +371,7 @@ static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
unsigned int clus)
{
return ((clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
return ((sector_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
sbi->data_start_sector;
}