From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> commit 43946b70494beefe40ec1b2ba4744c0f294d7736 upstream. 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: 1acf1a564b60 ("exfat: add in-memory and on-disk structures and headers") Cc: stable@xxxxxxxxxxxxxxx # v5.7 Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/exfat/exfat_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -375,7 +375,7 @@ static inline bool exfat_is_last_sector_ 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; }