diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
index ac22d8407a77..66411a712b14 100644
--- a/fs/ntfs/index.c
+++ b/fs/ntfs/index.c
@@ -489,6 +489,14 @@ static struct index_entry *ntfs_ie_dup_novcn(struct index_entry *ie)
 	return dup;
 }
 
+/* Offset of the first entry in an index block created by ntfs_ib_alloc(). */
+static u32 ntfs_ib_canonical_entries_offset(u32 block_size)
+{
+	u32 usa_count = block_size / NTFS_BLOCK_SIZE + 1;
+
+	return (sizeof(struct index_header) + usa_count * 2 + 7) & ~7;
+}
+
 /*
  * Check the consistency of an index block
  *
@@ -548,6 +556,16 @@ int ntfs_index_block_inconsistent(struct ntfs_volume *vol,
 					   offsetof(struct index_block, index),
 					   inum))
 		return -EIO;
+
+	if (le32_to_cpu(ib->index.entries_offset) <
+	    ntfs_ib_canonical_entries_offset(block_size)) {
+		ntfs_error(sb,
+			   "Index block: entries offset %u is below the minimum for a %u-byte block: vcn %lld inode %llu\n",
+			   le32_to_cpu(ib->index.entries_offset), block_size,
+			   vcn, inum);
+		return -EIO;
+	}
+
 	if (ntfs_index_entries_inconsistent(vol, &ib->index, cr, inum))
 		return -EIO;
 	return 0;
@@ -960,8 +978,8 @@ static struct index_block *ntfs_ib_alloc(s64 ib_vcn, u32 ib_size,
 	*(__le16 *)((char *)ib + le16_to_cpu(ib->usa_ofs)) = cpu_to_le16(1);
 	ib->lsn = 0;
 	ib->index_block_vcn = cpu_to_le64(ib_vcn);
-	ib->index.entries_offset = cpu_to_le32((ih_size +
-				le16_to_cpu(ib->usa_count) * 2 + 7) & ~7);
+	ib->index.entries_offset =
+		cpu_to_le32(ntfs_ib_canonical_entries_offset(ib_size));
 	ib->index.index_length = 0;
 	ib->index.allocated_size = cpu_to_le32(ib_size -
 			(sizeof(struct index_block) - ih_size));