[PATCH 5.19 040/207] exfat: fix overflow for large capacity partition

Greg Kroah-Hartman
2022-09-26T11:35:39Z

From: Yuezhang Mo <Yuezhang.Mo@sony.com>

commit 2e9ceb6728f1dc2fa4b5d08f37d88cbc49a20a62 upstream.

Using int type for sector index, there will be overflow in a large
capacity partition.

For example, if storage with sector size of 512 bytes and partition
capacity is larger than 2TB, there will be overflow.

Fixes: 1b6138385499 ("exfat: reduce block requests when zeroing a cluster")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/exfat/fatent.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c
index ee0b7cf51157..41ae4cce1f42 100644
--- a/fs/exfat/fatent.c
+++ b/fs/exfat/fatent.c
@@ -270,8 +270,7 @@ int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
struct super_block *sb = dir->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct buffer_head *bh;
- sector_t blknr, last_blknr;
- int i;
+ sector_t blknr, last_blknr, i;

blknr = exfat_cluster_to_sector(sbi, clu);
last_blknr = blknr + sbi->sect_per_clus;
--
2.37.3