[PATCH AUTOSEL 5.15 13/14] exfat: fix overflow in sector and cluster conversion

From: Sasha Levin
Date: Fri Dec 23 2022 - 20:36:50 EST


From: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>

[ Upstream commit 40306b4d1ba25970dafd53432e8daa5d591ebd99 ]

According to the exFAT specification, there are at most 2^32-11
clusters in a volume. so using 'int' is not enough for cluster
index, the return value type of exfat_sector_to_cluster() should
be 'unsigned int'.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/exfat/exfat_fs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 9f82a8a835ee..d99df8d83d38 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -374,7 +374,7 @@ static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
sbi->data_start_sector;
}

-static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
+static inline unsigned int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
sector_t sec)
{
return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
--
2.35.1