diff --git a/src/config_gram.y b/src/config_gram.y
index bd32de16..dfdf50b5 100644
--- a/src/config_gram.y
+++ b/src/config_gram.y
@@ -536,25 +536,22 @@ usb_pid_list:
   TKN_NUMBER {
     {
       /* overwrite pids, so clear the existing entries */
-      ldestroy_cb(current_prog->usbpid, free);
+      if(current_prog->usbpid)
+        ldestroy_cb(current_prog->usbpid, free);
       current_prog->usbpid = lcreat(NULL, 0);
     }
     {
-      int *ip = malloc(sizeof(int));
-      if (ip) {
-        *ip = $1->value.number;
-        ladd(current_prog->usbpid, ip);
-      }
+      int *ip = cfg_malloc("usb_pid_list", sizeof(int));
+      *ip = $1->value.number;
+      ladd(current_prog->usbpid, ip);
       free_token($1);
     }
   } |
   usb_pid_list TKN_COMMA TKN_NUMBER {
     {
-      int *ip = malloc(sizeof(int));
-      if (ip) {
-        *ip = $3->value.number;
-        ladd(current_prog->usbpid, ip);
-      }
+      int *ip = cfg_malloc("usb_pid_list", sizeof(int));
+      *ip = $3->value.number;
+      ladd(current_prog->usbpid, ip);
       free_token($3);
     }
   }
@@ -568,25 +565,22 @@ hvupdi_support_list:
   TKN_NUMBER {
     {
       /* overwrite list entries, so clear the existing entries */
-      ldestroy_cb(current_prog->hvupdi_support, free);
+      if(current_prog->hvupdi_support)
+        ldestroy_cb(current_prog->hvupdi_support, free);
       current_prog->hvupdi_support = lcreat(NULL, 0);
     }
     {
-      int *ip = malloc(sizeof(int));
-      if (ip) {
-        *ip = $1->value.number;
-        ladd(current_prog->hvupdi_support, ip);
-      }
+      int *ip = cfg_malloc("hvupdi_support_list", sizeof(int));
+      *ip = $1->value.number;
+      ladd(current_prog->hvupdi_support, ip);
       free_token($1);
     }
   } |
   hvupdi_support_list TKN_COMMA TKN_NUMBER {
     {
-      int *ip = malloc(sizeof(int));
-      if (ip) {
-        *ip = $3->value.number;
-        ladd(current_prog->hvupdi_support, ip);
-      }
+      int *ip = cfg_malloc("hvupdi_support_list", sizeof(int));
+      *ip = $3->value.number;
+      ladd(current_prog->hvupdi_support, ip);
       free_token($3);
     }
   }
diff --git a/src/pgm.c b/src/pgm.c
index 2880a212..4c2b7cee 100644
--- a/src/pgm.c
+++ b/src/pgm.c
@@ -152,12 +152,18 @@ PROGRAMMER *pgm_new(void) {
 
 void pgm_free(PROGRAMMER *p) {
   if(p) {
-    ldestroy_cb(p->id, free);
-    ldestroy_cb(p->usbpid, free);
-    ldestroy_cb(p->hvupdi_support, free);
-    p->id = NULL;
-    p->usbpid = NULL;
-    p->hvupdi_support = NULL;
+    if(p->id) {
+      ldestroy_cb(p->id, free);
+      p->id = NULL;
+    }
+    if(p->usbpid) {
+      ldestroy_cb(p->usbpid, free);
+      p->usbpid = NULL;
+    }
+    if(p->hvupdi_support) {
+      ldestroy_cb(p->hvupdi_support, free);
+      p->hvupdi_support = NULL;
+    }
     // Never free const char *, eg, p->desc, which are set by cache_string()
     // p->cookie is freed by pgm_teardown
     free(p);
@@ -168,22 +174,27 @@ PROGRAMMER *pgm_dup(const PROGRAMMER *src) {
   PROGRAMMER *pgm = pgm_new();
 
   if(src) {
+    ldestroy_cb(pgm->id, free);
+    ldestroy_cb(pgm->usbpid, free);
+    ldestroy_cb(pgm->hvupdi_support, free);
     memcpy(pgm, src, sizeof(*pgm));
     pgm->id = lcreat(NULL, 0);
     pgm->usbpid = lcreat(NULL, 0);
     pgm->hvupdi_support = lcreat(NULL, 0);
 
     // Leave id list empty but copy usbpid and hvupdi_support over
-    for(LNODEID ln = lfirst(src->hvupdi_support); ln; ln = lnext(ln)) {
-      int *ip = cfg_malloc("pgm_dup()", sizeof(int));
-      *ip = *(int *) ldata(ln);
-      ladd(pgm->hvupdi_support, ip);
-    }
-    for(LNODEID ln = lfirst(src->usbpid); ln; ln = lnext(ln)) {
-      int *ip = cfg_malloc("pgm_dup()", sizeof(int));
-      *ip = *(int *) ldata(ln);
-      ladd(pgm->usbpid, ip);
-    }
+    if(src->hvupdi_support)
+      for(LNODEID ln = lfirst(src->hvupdi_support); ln; ln = lnext(ln)) {
+        int *ip = cfg_malloc("pgm_dup()", sizeof(int));
+        *ip = *(int *) ldata(ln);
+        ladd(pgm->hvupdi_support, ip);
+      }
+    if(src->usbpid)
+      for(LNODEID ln = lfirst(src->usbpid); ln; ln = lnext(ln)) {
+        int *ip = cfg_malloc("pgm_dup()", sizeof(int));
+        *ip = *(int *) ldata(ln);
+        ladd(pgm->usbpid, ip);
+      }
   }
 
   return pgm;