diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index c55dc47d2261..b3e941423a3f 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1737,8 +1737,8 @@ static struct attr_def *ntfs_attr_find_in_attrdef(const struct ntfs_volume *vol,
 	struct attr_def *ad;
 
 	WARN_ON(!type);
-	for (ad = vol->attrdef; (u8 *)ad - (u8 *)vol->attrdef <
-			vol->attrdef_size && ad->type; ++ad) {
+	for (ad = vol->attrdef; (u8 *)ad - (u8 *)vol->attrdef <=
+	     vol->attrdef_size - (s32)sizeof(*ad) && ad->type; ++ad) {
 		/* We have not found it yet, carry on searching. */
 		if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
 			continue;
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 2df64712335a..155dca5db7a9 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -1241,9 +1241,9 @@ static bool load_and_init_attrdef(struct ntfs_volume *vol)
 		goto failed;
 	}
 	NInoSetSparseDisabled(NTFS_I(ino));
-	/* The size of FILE_AttrDef must be above 0 and fit inside 31 bits. */
+	/* FILE_AttrDef must hold at least one entry and fit inside 31 bits. */
 	i_size = i_size_read(ino);
-	if (i_size <= 0 || i_size > 0x7fffffff)
+	if (i_size < (s64)sizeof(struct attr_def) || i_size > 0x7fffffff)
 		goto iput_failed;
 	vol->attrdef = kvzalloc(i_size, GFP_NOFS);
 	if (!vol->attrdef)