[jcifs] Bug in JCIFS-0.7.0b12

MaWaismann at ifsc.de MaWaismann at ifsc.de
Wed Jan 8 20:43:04 EST 2003

Dear Mr. Allen,

using your library jcifs-0.7.0b12 I encountered a possible bug in the class
jcifs.netbios.NameServiceClient. There are the following code lines in the
constructor to initialize the resolve order:

            int[] tmp = new int[3];
            StringTokenizer st = new StringTokenizer( ro, "," );
            int i = 0;
            while( st.hasMoreTokens() ) {
                String s = st.nextToken().trim();
                if( s.equalsIgnoreCase( "LMHOSTS" )) {
                    tmp[i++] = RESOLVER_LMHOSTS;
                } else if( s.equalsIgnoreCase( "WINS" )) {
                    if( nbns == null ) {
                        Log.println( Log.WARNINGS, "netbios name service
                                " resolveOrder specifies WINS however the "
                                "jcifs.netbios.wins property has not been
set" );
                    tmp[i++] = RESOLVER_WINS;
                } else if( s.equalsIgnoreCase( "BCAST" )) {
                    tmp[i++] = RESOLVER_BCAST;
                } else if( s.equalsIgnoreCase( "DNS" )) {
                    i++; // skip
                } else {
                    Log.println( Log.WARNINGS, "netbios name service
                                "unknown resolver method: " + s );
            resolveOrder = new int[i];
            System.arraycopy( tmp, 0, resolveOrder, 0, i );

In the case of setting up the property
jcifs.resolveOrder=LMHOSTS,WINS,BCAST,DNS, the while loop is going through
four times. If the property jcifs.netbios.wins is set too, i has the value 4
at the end of the while loop.

Therefore the method System.arraycopy is called with the parameter (tmp[3],
0, resolveOrder, 0, 4) and throws the
java.lang.ArrayIndexOutOfBoundsException, because the length of the array
tmp is 3 instead of 4.

If the token is "DNS" in the while loop, i should not be incremented. 

Yours sincerely,
Marco Waismann
ifsc informationservices gmbh
email: MaWaismann at ifsc.de

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