diff -Nru ifupdown-0.7.2ubuntu2/debian/changelog ifupdown-0.7.2ubuntu3~lp1160490/debian/changelog
--- ifupdown-0.7.2ubuntu2/debian/changelog	2012-10-09 10:13:28.000000000 -0500
+++ ifupdown-0.7.2ubuntu3~lp1160490/debian/changelog	2013-08-20 17:03:26.000000000 -0500
@@ -1,3 +1,10 @@
+ifupdown (0.7.2ubuntu3) quantal; urgency=low
+
+  * Race condition updating statefile. (LP: #1160490)
+    http://anonscm.debian.org/hg/collab-maint/ifupdown/rev/a93db3ecb8f0
+
+ -- Chris J Arges <chris.j.arges@canonical.com>  Tue, 20 Aug 2013 16:50:22 -0500
+
 ifupdown (0.7.2ubuntu2) quantal; urgency=low
 
   * Fix regression with the removal of the sysvinit networking job:
diff -Nru ifupdown-0.7.2ubuntu2/ifupdown.nw ifupdown-0.7.2ubuntu3~lp1160490/ifupdown.nw
--- ifupdown-0.7.2ubuntu2/ifupdown.nw	2012-09-12 15:33:58.000000000 -0500
+++ ifupdown-0.7.2ubuntu3~lp1160490/ifupdown.nw	2013-08-20 16:50:17.000000000 -0500
@@ -3634,8 +3634,9 @@
 int no_act = 0;
 int run_scripts = 1;
 int verbose = 0;
-char *statefile = RUN_DIR "ifstate";
-char *tmpstatefile = RUN_DIR ".ifstate.tmp";
+char lockfile[] = RUN_DIR ".ifstate.lock";
+char statefile[] = RUN_DIR "ifstate";
+char tmpstatefile[] = RUN_DIR ".ifstate.tmp";
 char *nm_system_settings = "/etc/NetworkManager/NetworkManager.conf";
 @
 
@@ -4398,6 +4399,37 @@
 static void update_state(const char *argv0, const char *iface, const char *liface);
 @ 
 
+<<main functions>>=
+FILE *
+lock_state (const char * argv0)
+{
+	FILE *lock_fp;
+	lock_fp = fopen(lockfile, no_act ? "r" : "a+");
+	if (lock_fp == NULL) {
+		if (!no_act) {
+			fprintf(stderr, "%s: failed to open lockfile %s: %s\n", argv0, lockfile, strerror(errno));
+			exit(1);
+		} else {
+			return NULL;
+		}
+	}
+
+	int flags;
+
+	if ((flags = fcntl(fileno(lock_fp), F_GETFD)) < 0 || fcntl(fileno(lock_fp), F_SETFD, flags | FD_CLOEXEC) < 0) {
+		fprintf(stderr, "%s: failed to set FD_CLOEXEC on lockfile %s: %s\n", argv0, lockfile, strerror(errno));
+		exit(1);
+	}
+
+	if (lock_fd(fileno(lock_fp)) < 0) {
+		fprintf(stderr, "%s: failed to lock lockfile %s: %s\n", argv0, lockfile, strerror(errno));
+		exit(1);
+	}
+
+	return lock_fp;
+}
+@
+
 The first of these functions reads the state file to look for an interface
 and returns the current state of it as a pointer to a static buffer which
 should be copied if it's needed for any duration.  If the interface has no
@@ -4542,10 +4574,13 @@
 @ 
 
 <<open ifupdown state>>=
+FILE *lock_fp;
 FILE *state_fp;
 char buf[80];
 char *p;
 
+lock_fp = lock_state(argv0);
+
 state_fp = fopen(statefile, no_act ? "r" : "a+");
 if (state_fp == NULL) {
 	if (!no_act) {
@@ -4568,13 +4603,6 @@
 			argv0, statefile, strerror(errno));
 		exit(1);
 	}
-
-	if (lock_fd (fileno(state_fp)) < 0) {
-		fprintf(stderr, 
-			"%s: failed to lock statefile %s: %s\n",
-			argv0, statefile, strerror(errno));
-		exit(1);
-	}
 }
 @
 
@@ -4595,6 +4623,10 @@
 	fclose(state_fp);
 	state_fp = NULL;
 }
+if (lock_fp != NULL) {
+	fclose(lock_fp);
+	lock_fp = NULL;
+}
 @
 
 This leaves our two useful chunks. The first checks to ensure what we're