/* ppid */
                         sprintf(filename, "%d/stat", pid);
                         fd = openat(procfd, filename, O_RDONLY);
+                        if (fd == -1)
+                                continue;
                         st = fdopen(fd, "r");
-                        if (!st)
+                        if (!st) {
+                                close(fd);
                                 continue;
+                        }
                         if (!fscanf(st, "%*s %*s %*s %i", &p)) {
                                 continue;
                         }
                 if (!ps->smaps) {
                         sprintf(filename, "%d/smaps", pid);
                         fd = openat(procfd, filename, O_RDONLY);
+                        if (fd == -1)
+                                continue;
                         ps->smaps = fdopen(fd, "r");
-                        if (!ps->smaps)
+                        if (!ps->smaps) {
+                                close(fd);
                                 continue;
+                        }
                         setvbuf(ps->smaps, smaps_buf, _IOFBF, sizeof(smaps_buf));
                 }
                 else {
 
                 if (!fgets(cmdline, 255, f))
                         sprintf(cmdline, "Unknown");
                 fclose(f);
+        } else {
+                if (fd >= 0)
+                        close(fd);
         }
 
         /* extract root fs so we can find disk model name in sysfs */
                         if (!fgets(model, 255, f))
                                 fprintf(stderr, "Error reading disk model for %s\n", rootbdev);
                         fclose(f);
+                } else {
+                        if (fd >= 0)
+                                close(fd);
                 }
         }
 
                         }
                 }
                 fclose(f);
+        } else {
+                if (fd >= 0)
+                        close(fd);
         }
 
         svg("<text class=\"t1\" x=\"0\" y=\"30\">Bootchart for %s - %s</text>\n",