fs/ntfs3: Fix field-spanning write in INDEX_HDR

[ Upstream commit 2f3e176fee66ac86ae387787bf06457b101d9f7a ]

Fields flags and res[3] replaced with one 4 byte flags.

Fixes: 4534a70b70 ("fs/ntfs3: Add headers and misc files")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/ntfs3/index.c

@@ -979,7 +979,7 @@ static struct indx_node *indx_new(struct ntfs_index *indx,
 		hdr->used =
 			cpu_to_le32(eo + sizeof(struct NTFS_DE) + sizeof(u64));
 		de_set_vbn_le(e, *sub_vbn);
-		hdr->flags = 1;
+		hdr->flags = NTFS_INDEX_HDR_HAS_SUBNODES;
 	} else {
 		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
 		hdr->used = cpu_to_le32(eo + sizeof(struct NTFS_DE));
@@ -1684,7 +1684,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
 	e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
 	e->flags = NTFS_IE_HAS_SUBNODES | NTFS_IE_LAST;
 
-	hdr->flags = 1;
+	hdr->flags = NTFS_INDEX_HDR_HAS_SUBNODES;
 	hdr->used = hdr->total =
 		cpu_to_le32(new_root_size - offsetof(struct INDEX_ROOT, ihdr));
 

fs/ntfs3/ntfs.h

@@ -686,14 +686,15 @@ static inline bool de_has_vcn_ex(const struct NTFS_DE *e)
 	      offsetof(struct ATTR_FILE_NAME, name) + \
 	      NTFS_NAME_LEN * sizeof(short), 8)
 
+#define NTFS_INDEX_HDR_HAS_SUBNODES cpu_to_le32(1)
+
 struct INDEX_HDR {
 	__le32 de_off;	// 0x00: The offset from the start of this structure
 			// to the first NTFS_DE.
 	__le32 used;	// 0x04: The size of this structure plus all
 			// entries (quad-word aligned).
 	__le32 total;	// 0x08: The allocated size of for this structure plus all entries.
-	u8 flags;	// 0x0C: 0x00 = Small directory, 0x01 = Large directory.
-	u8 res[3];
+	__le32 flags;	// 0x0C: 0x00 = Small directory, 0x01 = Large directory.
 
 	//
 	// de_off + used <= total
@@ -740,7 +741,7 @@ static inline struct NTFS_DE *hdr_next_de(const struct INDEX_HDR *hdr,
 
 static inline bool hdr_has_subnode(const struct INDEX_HDR *hdr)
 {
-	return hdr->flags & 1;
+	return hdr->flags & NTFS_INDEX_HDR_HAS_SUBNODES;
 }
 
 struct INDEX_BUFFER {
@@ -760,7 +761,7 @@ static inline bool ib_is_empty(const struct INDEX_BUFFER *ib)
 
 static inline bool ib_is_leaf(const struct INDEX_BUFFER *ib)
 {
-	return !(ib->ihdr.flags & 1);
+	return !(ib->ihdr.flags & NTFS_INDEX_HDR_HAS_SUBNODES);
 }
 
 /* Index root structure ( 0x90 ). */