[PATCH AUTOSEL 6.5 07/52] fs/ntfs3: Fix shift-out-of-bounds in ntfs_fill_super

[Sasha Levin]

From: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>

[ Upstream commit 91a4b1ee78cb100b19b70f077c247f211110348f ]

Reported-by: syzbot+478c1bf0e6bf4a8f3a04@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ntfs3/ntfs_fs.h |  2 ++
 fs/ntfs3/super.c   | 26 ++++++++++++++++++++------
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 629403ede6e5f..788567d71d939 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -42,9 +42,11 @@ enum utf16_endian;
 #define MINUS_ONE_T			((size_t)(-1))
 /* Biggest MFT / smallest cluster */
 #define MAXIMUM_BYTES_PER_MFT		4096
+#define MAXIMUM_SHIFT_BYTES_PER_MFT	12
 #define NTFS_BLOCKS_PER_MFT_RECORD	(MAXIMUM_BYTES_PER_MFT / 512)
 
 #define MAXIMUM_BYTES_PER_INDEX		4096
+#define MAXIMUM_SHIFT_BYTES_PER_INDEX	12
 #define NTFS_BLOCKS_PER_INODE		(MAXIMUM_BYTES_PER_INDEX / 512)
 
 /* NTFS specific error code when fixup failed. */
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index d3c78e2a49cbe..18a8bc73b8e2d 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -901,9 +901,17 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 		goto out;
 	}
 
-	sbi->record_size = record_size =
-		boot->record_size < 0 ? 1 << (-boot->record_size) :
-					(u32)boot->record_size << cluster_bits;
+	if (boot->record_size >= 0) {
+		record_size = (u32)boot->record_size << cluster_bits;
+	} else if (-boot->record_size <= MAXIMUM_SHIFT_BYTES_PER_MFT) {
+		record_size = 1u << (-boot->record_size);
+	} else {
+		ntfs_err(sb, "%s: invalid record size %d.", hint,
+			 boot->record_size);
+		goto out;
+	}
+
+	sbi->record_size = record_size;
 	sbi->record_bits = blksize_bits(record_size);
 	sbi->attr_size_tr = (5 * record_size >> 4); // ~320 bytes
 
@@ -920,9 +928,15 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 		goto out;
 	}
 
-	sbi->index_size = boot->index_size < 0 ?
-				  1u << (-boot->index_size) :
-				  (u32)boot->index_size << cluster_bits;
+	if (boot->index_size >= 0) {
+		sbi->index_size = (u32)boot->index_size << cluster_bits;
+	} else if (-boot->index_size <= MAXIMUM_SHIFT_BYTES_PER_INDEX) {
+		sbi->index_size = 1u << (-boot->index_size);
+	} else {
+		ntfs_err(sb, "%s: invalid index size %d.", hint,
+			 boot->index_size);
+		goto out;
+	}
 
 	/* Check index record size. */
 	if (sbi->index_size < SECTOR_SIZE || !is_power_of_2(sbi->index_size)) {
-- 
2.42.0