From 09f7c338da7818fd33af401d855b895550e7c170 Mon Sep 17 00:00:00 2001

From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

Date: Tue, 28 Sep 2021 19:19:17 +0300

Subject: [Backport 09f7c338da78] src: Reject mount if boot's cluster size

 < media sector size

If we continue to work in this case, then we can corrupt fs.

Fixes: 82cae269cfa9 ("src: Add initialization of super block").

Reviewed-by: Kari Argillander <kari.argillander@gmail.com>

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

---

 src/super.c | 13 ++++++++++++-

 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/super.c b/src/super.c

index 800897777eb03855f702e8acf15b39d02c1c2fbf..e9b6a37345769700f682809832d84d8dfc7b9414 100644

--- a/src/super.c

+++ b/src/super.c

@@ -763,9 +763,20 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,

 	sbi->mft.lbo = mlcn << sbi->cluster_bits;

 	sbi->mft.lbo2 = mlcn2 << sbi->cluster_bits;

-	if (sbi->cluster_size < sbi->sector_size)

+	/* Compare boot's cluster and sector. */

+	if (sbi->cluster_size < boot_sector_size)

 		goto out;

+	/* Compare boot's cluster and media sector. */

+	if (sbi->cluster_size < sector_size) {

+		/* No way to use ntfs_get_block in this case. */

+		ntfs_err(

+			sb,

+			"Failed to mount 'cause NTFS's cluster size (%u) is less than media sector size (%u)",

+			sbi->cluster_size, sector_size);

+		goto out;

+	}

+

 	sbi->cluster_mask = sbi->cluster_size - 1;

 	sbi->cluster_mask_inv = ~(u64)sbi->cluster_mask;

 	sbi->record_size = record_size = boot->record_size < 0

-- 

2.31.1