exfat: fix overflow in sector and cluster conversion

YuezhangMo · namjaejeon · commit 40306b4d1ba2 · 2022-12-13T20:17:11.000+09:00
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 &lt;Yuezhang.Mo@sony.com&gt;
Reviewed-by: Sungjong Seo &lt;sj1557.seo@samsung.com&gt;
Signed-off-by: Namjae Jeon &lt;linkinjeon@kernel.org&gt;
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
@@ -400,7 +400,7 @@ 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) +

Original file line number	Diff line number	Diff line change
`@@ -400,7 +400,7 @@ static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,`
`400`	`400`	`sbi->data_start_sector;`
`401`	`401`	`}`
`402`	`402`
`403`		`-static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,`
	`403`	`+static inline unsigned int exfat_sector_to_cluster(struct exfat_sb_info *sbi,`
`404`	`404`	`sector_t sec)`
`405`	`405`	`{`
`406`	`406`	`return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +`