exfat: fix overflow issue in exfat_cluster_to_sector()

An overflow issue can occur at sector calculation in exfat_cluster_to_sector(). It needs to cast clus's type to sector_t before left shifting. Signed-off-by: Namjae Jeon <[email protected]>
PixelExperience-Devices · Jul 3, 2020 · 9cbc7e4 · 9cbc7e4
1 parent d7fd859
commit 9cbc7e4
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/exfat_fs.h b/exfat_fs.h
@@ -381,7 +381,7 @@ 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;
 }