diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index f473ddf0bd949f477db42d7f7145c412b67dc815..5c4861210d4c9f97b201623a03366b27d8b37eca 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -779,6 +779,11 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		ix = curp->p_idx;
 	}
 
+	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+		return -EIO;
+	}
+
 	ix->ei_block = cpu_to_le32(logical);
 	ext4_idx_store_pblock(ix, ptr);
 	le16_add_cpu(&curp->p_hdr->eh_entries, 1);