vxlan_duplicate_fdb_test.pl

#!/usr/bin/perl

use strict;
use warnings;

sub append_fdb_entries {
    my $vtep = shift;
    for (;;) {
        my $pid = fork();
        if (not defined $pid) {
            die("fork: $!");
        } elsif ($pid == 0) {
            my $ip = "192.0.2." . (100 + int(rand(100)));
            exec('/sbin/bridge', 'fdb', 'append', '00:00:00:00:00:00',
                 'dev', $vtep, 'dst', $ip);
            die("exec: $!");
        }
        waitpid($pid, 0);
    }
}

sub main {
    my $vtep = 'vxlan-1';

    system('ip', 'link', 'add', $vtep, 'type', 'vxlan',
           'id', '1', 'dev', 'eth0');
	
    for (my $i = 0; $i < 16; $i++) {
        my $pid = fork();
        if (not defined $pid) {
            die("fork: $!");
        } elsif ($pid == 0) {
	    # Child
            append_fdb_entries($vtep);
            exit(0);
        }
    }
    for (;;) {
        sleep(1);
    }
}

main();

This script can insert duplicate FDB entries under 3.13.0-23-generic.

Verified issue still occurs on 3.13.0-83-generic