At line 1949 of head/contrib/bsnmp/lib/snmpclient.c, you changed .. - if ((sc->chost = malloc(strlen(s) + 1)) == NULL) { + if ((sc->chost = strdup(strlen(s))) == NULL) { This can't work as intended since strlen returns the length of the string not a pointer to it. I expect this should be .. if ((sc->chost = strdup(s)) == NULL) { Michael