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

Sasha Levin
2023-10-29T22:54:55Z

[ Upstream commit 91a4b1ee78cb100b19b70f077c247f211110348f ]

Reported-by: syzbot+478c1bf0e6bf4a8f3a04@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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