Routes learnt from both ISIS and BGP (mostly when we BGP NNI and inter-as scenarios)and if we redistribute them  into LDP the core might be seen when there is a churn in the network ie route might be flapping, in this case when ISIS is trying to access the memory but it will not be present as the route has flapped which will cause the core dump.

policy-statement LDP {
        term a {
            from {
                protocol [ direct local ];
                route-filter x.x.x.x/32 exact;
                route-filter y.y.y.y/32 exact;
                route-filter z.z.z.z./32 exact;
            }
            then accept;
        }
        term 10 {
            from {
                protocol bgp;
                neighbor a.b.c.d;
            }
            then {
                tag tag;
                accept;
            }

x.x.x.x/27   *[IS-IS/18] 2d 03:18:56, metric 70, tag tag
                    >  to 192.168.1.1 via ae.*
                       to 192.168.1.2 via ge-*

Delete the export policies where we are advertising the routes learnt from BGP-LU from different AS into ISIS and LDP.