daemon: debug segv correct use of dereferencing NULL.

[libguestfs.git] / daemon / inotify.c

diff --git a/daemon/inotify.c b/daemon/inotify.c
index 807fb2f..3fc7b92 100644 (file)
--- a/daemon/inotify.c
+++ b/daemon/inotify.c
@@ -1,5 +1,5 @@
 /* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc.
+ * Copyright (C) 2009-2011 Red Hat Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #include <config.h>
@@ -70,7 +70,7 @@ do_inotify_init (int max_events)
 #ifdef HAVE_SYS_INOTIFY_H
   FILE *fp;
 
-  NEED_ROOT (0, return -1);
+  NEED_ROOT (, return -1);
 
   if (max_events < 0) {
     reply_with_error ("max_events < 0");
@@ -314,13 +314,24 @@ do_inotify_files (void)
   char **ret = NULL;
   int size = 0, alloc = 0;
   unsigned int i;
-  FILE *fp;
+  FILE *fp = NULL;
   guestfs_int_inotify_event_list *events;
   char buf[PATH_MAX];
+  char tempfile[] = "/tmp/inotifyXXXXXX";
+  int fd;
+  char cmd[64];
 
   NEED_INOTIFY (NULL);
 
-  fp = popen ("sort -u > /tmp/inotify", "w");
+  fd = mkstemp (tempfile);
+  if (fd == -1) {
+    reply_with_perror ("mkstemp");
+    return NULL;
+  }
+
+  snprintf (cmd, sizeof cmd, "sort -u > %s", tempfile);
+
+  fp = popen (cmd, "w");
   if (fp == NULL) {
     reply_with_perror ("sort");
     return NULL;
@@ -349,9 +360,11 @@ do_inotify_files (void)
 
   pclose (fp);
 
-  fp = fopen ("/tmp/inotify", "r");
+  fp = fdopen (fd, "r");
   if (fp == NULL) {
-    reply_with_perror ("/tmp/inotify");
+    reply_with_perror ("%s", tempfile);
+    unlink (tempfile);
+    close (fd);
     return NULL;
   }
 
@@ -361,22 +374,24 @@ do_inotify_files (void)
     if (len > 0 && buf[len-1] == '\n')
       buf[len-1] = '\0';
 
-    if (add_string (&ret, &size, &alloc, buf) == -1) {
-      fclose (fp);
+    if (add_string (&ret, &size, &alloc, buf) == -1)
       goto error;
-    }
   }
 
-  fclose (fp);
+  fclose (fp); /* implicitly closes fd */
+  fp = NULL;
 
   if (add_string (&ret, &size, &alloc, NULL) == -1)
     goto error;
 
-  unlink ("/tmp/inotify");
+  unlink (tempfile);
   return ret;
 
  error:
-  unlink ("/tmp/inotify");
+  if (fp != NULL)
+    fclose (fp);
+
+  unlink (tempfile);
   return NULL;
 #else
   NOT_AVAILABLE (NULL);