diff -Naur psmisc-22.20.orig/src/pstree.c psmisc-22.20/src/pstree.c
--- psmisc-22.20.orig/src/pstree.c	2013-10-21 15:31:15.000000000 +0200
+++ psmisc-22.20/src/pstree.c	2013-10-21 15:30:58.000000000 +0200
@@ -222,7 +222,12 @@
     }
 
     if (!ptr) {
-        ptr = malloc(sizeof(*ptr));
+
+        if (!(ptr = malloc(sizeof(*ptr)))) {
+            perror("malloc");
+            exit(1);
+        }
+
         memset(ptr, 0, sizeof(*ptr));
         ptr->number = r->ns[id];
         if (*root == NULL)
@@ -234,7 +239,12 @@
     /* move the child to under the namespace's umbrella */
     for (c = &ptr->children; *c; c = &(*c)->next)
         ;
-    *c = malloc(sizeof(CHILD));
+
+    if (!(*c = malloc(sizeof(CHILD)))) {
+        perror("malloc");
+        exit(1);
+    }
+
     (*c)->child = r;
     (*c)->next = NULL;