Commit 43946b70 authored Jul 03, 2020 by Namjae Jeon

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: 1acf1a56 ("exfat: add in-memory and on-disk structures and headers")
Cc: stable@vger.kernel.org # v5.7
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

parent ba47d845

fs/exfat/exfat_fs.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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