From 43946b70494beefe40ec1b2ba4744c0f294d7736 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Fri, 3 Jul 2020 11:16:32 +0900 Subject: [Backport 43946b70494b] 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: 1acf1a564b60 ("exfat: add in-memory and on-disk structures and headers") Cc: stable@vger.kernel.org # v5.7 Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon --- src/exfat_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/exfat_fs.h b/src/exfat_fs.h index 7579cd3bbadba87a8bfd56c0699c8186902a6763..75c7bdbeba6d3e9316c7b795cd525d1323e47b83 100644 --- a/src/exfat_fs.h +++ b/src/exfat_fs.h @@ -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; } -- 2.31.1