Normalization of Many to Many relation in sql

I have a product table that contains two column

ProductID   Desc
  1         Fan
  2         Table
  3         Bulb

I have another table that contains supplier information

SupplierID    Desc
   1          ABC
   2          XYZ
   3          HJK

Now One supplier can supply multiple products and one product can be supplied by multiple suppliers To achieve this I have created another table tbl_Supplier_Product

 SupplierID    ProductID 
     1            1
     1            2
     2            1
     2            2
     2            3

Is it a good way to link this table to supplier and product table through primary composite key. In this table the primary key would be a composite key (SupplierID and ProductID) or should I add an extra column row ID for each record and then use that as a primary key and add a unique constraint to columns SupplierID and ProductID

 SupplierID    ProductID    Row ID
         1            1       1
         1            2       2
         2            1       3
         2            2       4
         2            3       5
UNIQUE CONSTRAINT(SupplierID, ProductID)

What would the relationship of this table be to supplier table? I am a bit confused here because I added this table to resolve many to many relationship and redundant data but it still seems like this table has many to many relationship with both the tables??

You don't need the extra column: a composite key is all you need

I would create a unique index that is the reverse of the PK too: this is useful for many queries and also provides an FK index for ProductID

After comment:

CREATE TABLE SupplierProduct (
    SupplierID int NOT NULL,
    ProductID int NOT NULL,

    PRIMARY KEY (SupplierID, ProductID)
);
GO
CREATE UNIQUE NONCLUSTERED INDEX IXU_ReversePK ON SupplierProduct (ProductID, SupplierID);
GO

For more

SQL: Do you need an auto-incremental primary key for Many-Many tables? for more (see comments)
Difference between 2 indexes with columns defined in reverse order

And also use this generally to ensure that all your FKs have indexes

SELECT  fk.name AS [Missing FK Index]
FROM    sys.foreign_keys fk
WHERE   EXISTS
        (
        SELECT  *
        FROM    sys.foreign_key_columns fkc
        WHERE   fkc.constraint_object_id = fk.object_id
                AND NOT EXISTS
                (
                SELECT  *
                FROM    sys.index_columns ic
                WHERE   ic.object_id = fkc.parent_object_id
                        AND ic.column_id = fkc.parent_column_id
                        AND ic.index_column_id = fkc.constraint_column_id
                )
        );
GO

In an ERD (random one from a PowerPoint I have):