fs/ntfs3: Add more attributes checks in mi_enum_attr()

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

Author: aalexandrovich

fs/ntfs3/record.c

@@ -193,8 +193,9 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 {
 	const struct MFT_REC *rec = mi->mrec;
 	u32 used = le32_to_cpu(rec->used);
-	u32 t32, off, asize;
+	u32 t32, off, asize, prev_type;
 	u16 t16;
+	u64 data_size, alloc_size, tot_size;
 
 	if (!attr) {
 		u32 total = le32_to_cpu(rec->total);
@@ -213,6 +214,7 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 		if (!is_rec_inuse(rec))
 			return NULL;
 
+		prev_type = 0;
 		attr = Add2Ptr(rec, off);
 	} else {
 		/* Check if input attr inside record. */
@@ -226,11 +228,11 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 			return NULL;
 		}
 
-		if (off + asize < off) {
-			/* Overflow check. */
+		/* Overflow check. */
+		if (off + asize < off)
 			return NULL;
-		}
 
+		prev_type = le32_to_cpu(attr->type);
 		attr = Add2Ptr(attr, asize);
 		off += asize;
 	}
@@ -250,7 +252,11 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 
 	/* 0x100 is last known attribute for now. */
 	t32 = le32_to_cpu(attr->type);
-	if ((t32 & 0xf) || (t32 > 0x100))
+	if (!t32 || (t32 & 0xf) || (t32 > 0x100))
+		return NULL;
+
+	/* attributes in record must be ordered by type */
+	if (t32 < prev_type)
 		return NULL;
 
 	/* Check overflow and boundary. */
@@ -259,16 +265,15 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 
 	/* Check size of attribute. */
 	if (!attr->non_res) {
+		/* Check resident fields. */
 		if (asize < SIZEOF_RESIDENT)
 			return NULL;
 
 		t16 = le16_to_cpu(attr->res.data_off);
-
 		if (t16 > asize)
 			return NULL;
 
-		t32 = le32_to_cpu(attr->res.data_size);
-		if (t16 + t32 > asize)
+		if (t16 + le32_to_cpu(attr->res.data_size) > asize)
 			return NULL;
 
 		t32 = sizeof(short) * attr->name_len;
@@ -278,21 +283,52 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 		return attr;
 	}
 
-	/* Check some nonresident fields. */
-	if (attr->name_len &&
-	    le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
-		    le16_to_cpu(attr->nres.run_off)) {
+	/* Check nonresident fields. */
+	if (attr->non_res != 1)
+		return NULL;
+
+	t16 = le16_to_cpu(attr->nres.run_off);
+	if (t16 > asize)
+		return NULL;
+
+	t32 = sizeof(short) * attr->name_len;
+	if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
+		return NULL;
+
+	/* Check start/end vcn. */
+	if (le64_to_cpu(attr->nres.svcn) > le64_to_cpu(attr->nres.evcn) + 1)
+		return NULL;
+
+	data_size = le64_to_cpu(attr->nres.data_size);
+	if (le64_to_cpu(attr->nres.valid_size) > data_size)
 		return NULL;
-	}
 
-	if (attr->nres.svcn || !is_attr_ext(attr)) {
+	alloc_size = le64_to_cpu(attr->nres.alloc_size);
+	if (data_size > alloc_size)
+		return NULL;
+
+	t32 = mi->sbi->cluster_mask;
+	if (alloc_size & t32)
+		return NULL;
+
+	if (!attr->nres.svcn && is_attr_ext(attr)) {
+		/* First segment of sparse/compressed attribute */
+		if (asize + 8 < SIZEOF_NONRESIDENT_EX)
+			return NULL;
+
+		tot_size = le64_to_cpu(attr->nres.total_size);
+		if (tot_size & t32)
+			return NULL;
+
+		if (tot_size > alloc_size)
+			return NULL;
+	} else {
 		if (asize + 8 < SIZEOF_NONRESIDENT)
 			return NULL;
 
 		if (attr->nres.c_unit)
 			return NULL;
-	} else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
-		return NULL;
+	}
 
 	return attr;
 }