diff -up dhcp-4.3.3b1/client/clparse.c.cloexec dhcp-4.3.3b1/client/clparse.c

--- dhcp-4.3.3b1/client/clparse.c.cloexec	2015-08-10 10:46:20.264755543 +0200

+++ dhcp-4.3.3b1/client/clparse.c	2015-08-10 10:46:20.274755510 +0200

@@ -247,7 +247,7 @@ int read_client_conf_file (const char *n

 	int token;

 	isc_result_t status;

-	if ((file = open (name, O_RDONLY)) < 0)

+	if ((file = open (name, O_RDONLY | O_CLOEXEC)) < 0)

 		return uerr2isc (errno);

 	cfile = NULL;

@@ -323,7 +323,7 @@ void read_client_leases ()

 	/* Open the lease file.   If we can't open it, just return -

 	   we can safely trust the server to remember our state. */

-	if ((file = open (path_dhclient_db, O_RDONLY)) < 0)

+	if ((file = open (path_dhclient_db, O_RDONLY | O_CLOEXEC)) < 0)

 		return;

 	cfile = NULL;

diff -up dhcp-4.3.3b1/client/dhclient.c.cloexec dhcp-4.3.3b1/client/dhclient.c

--- dhcp-4.3.3b1/client/dhclient.c.cloexec	2015-08-10 10:46:20.260755556 +0200

+++ dhcp-4.3.3b1/client/dhclient.c	2015-08-10 10:46:20.275755506 +0200

@@ -153,11 +153,11 @@ main(int argc, char **argv) {

 	/* Make sure that file descriptors 0 (stdin), 1, (stdout), and

 	   2 (stderr) are open. To do this, we assume that when we

 	   open a file the lowest available file descriptor is used. */

-	fd = open("/dev/null", O_RDWR);

+	fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 0)

-		fd = open("/dev/null", O_RDWR);

+		fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 1)

-		fd = open("/dev/null", O_RDWR);

+		fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 2)

 		log_perror = 0; /* No sense logging to /dev/null. */

 	else if (fd != -1)

@@ -519,7 +519,7 @@ main(int argc, char **argv) {

 		long temp;

 		int e;

-		if ((pidfd = fopen(path_dhclient_pid, "r")) != NULL) {

+		if ((pidfd = fopen(path_dhclient_pid, "re")) != NULL) {

 			e = fscanf(pidfd, "%ld\n", &temp);

 			oldpid = (pid_t)temp;

@@ -574,7 +574,7 @@ main(int argc, char **argv) {

 					strncpy(new_path_dhclient_pid, path_dhclient_pid, pfx);

 					sprintf(new_path_dhclient_pid + pfx, "-%s.pid", ip->name);

-					if ((pidfd = fopen(new_path_dhclient_pid, "r")) != NULL) {

+					if ((pidfd = fopen(new_path_dhclient_pid, "re")) != NULL) {

 						e = fscanf(pidfd, "%ld\n", &temp);

 						oldpid = (pid_t)temp;

@@ -599,7 +599,7 @@ main(int argc, char **argv) {

 		int dhc_running = 0;

 		char procfn[256] = "";

-		if ((pidfp = fopen(path_dhclient_pid, "r")) != NULL) {

+		if ((pidfp = fopen(path_dhclient_pid, "re")) != NULL) {

 			if ((fscanf(pidfp, "%ld", &temp)==1) && ((dhcpid=(pid_t)temp) > 0)) {

 				snprintf(procfn,256,"/proc/%u",dhcpid);

 				dhc_running = (access(procfn, F_OK) == 0);

@@ -3120,7 +3120,7 @@ void rewrite_client_leases ()

 	if (leaseFile != NULL)

 		fclose (leaseFile);

-	leaseFile = fopen (path_dhclient_db, "w");

+	leaseFile = fopen (path_dhclient_db, "we");

 	if (leaseFile == NULL) {

 		log_error ("can't create %s: %m", path_dhclient_db);

 		return;

@@ -3313,7 +3313,7 @@ write_duid(struct data_string *duid)

 		return DHCP_R_INVALIDARG;

 	if (leaseFile == NULL) {	/* XXX? */

-		leaseFile = fopen(path_dhclient_db, "w");

+		leaseFile = fopen(path_dhclient_db, "we");

 		if (leaseFile == NULL) {

 			log_error("can't create %s: %m", path_dhclient_db);

 			return ISC_R_IOERROR;

@@ -3493,7 +3493,7 @@ int write_client_lease (client, lease, r

 		return 1;

 	if (leaseFile == NULL) {	/* XXX */

-		leaseFile = fopen (path_dhclient_db, "w");

+		leaseFile = fopen (path_dhclient_db, "we");

 		if (leaseFile == NULL) {

 			log_error ("can't create %s: %m", path_dhclient_db);

 			return 0;

@@ -4011,9 +4011,9 @@ void go_daemon ()

 	(void) close(2);

 	/* Reopen them on /dev/null. */

-	(void) open("/dev/null", O_RDWR);

-	(void) open("/dev/null", O_RDWR);

-	(void) open("/dev/null", O_RDWR);

+	(void) open("/dev/null", O_RDWR | O_CLOEXEC);

+	(void) open("/dev/null", O_RDWR | O_CLOEXEC);

+	(void) open("/dev/null", O_RDWR | O_CLOEXEC);

 	write_client_pid_file ();

@@ -4030,14 +4030,14 @@ void write_client_pid_file ()

 		return;

 	}

-	pfdesc = open (path_dhclient_pid, O_CREAT | O_TRUNC | O_WRONLY, 0644);

+	pfdesc = open (path_dhclient_pid, O_CREAT | O_TRUNC | O_WRONLY | O_CLOEXEC, 0644);

 	if (pfdesc < 0) {

 		log_error ("Can't create %s: %m", path_dhclient_pid);

 		return;

 	}

-	pf = fdopen (pfdesc, "w");

+	pf = fdopen (pfdesc, "we");

 	if (!pf) {

 		close(pfdesc);

 		log_error ("Can't fdopen %s: %m", path_dhclient_pid);

diff -up dhcp-4.3.3b1/common/bpf.c.cloexec dhcp-4.3.3b1/common/bpf.c

--- dhcp-4.3.3b1/common/bpf.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/common/bpf.c	2015-08-10 10:46:20.275755506 +0200

@@ -95,7 +95,7 @@ int if_register_bpf (info)

 	for (b = 0; 1; b++) {

 		/* %Audit% 31 bytes max. %2004.06.17,Safe% */

 		sprintf(filename, BPF_FORMAT, b);

-		sock = open (filename, O_RDWR, 0);

+		sock = open (filename, O_RDWR | O_CLOEXEC, 0);

 		if (sock < 0) {

 			if (errno == EBUSY) {

 				continue;

diff -up dhcp-4.3.3b1/common/dlpi.c.cloexec dhcp-4.3.3b1/common/dlpi.c

--- dhcp-4.3.3b1/common/dlpi.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/common/dlpi.c	2015-08-10 10:46:20.275755506 +0200

@@ -804,7 +804,7 @@ dlpiopen(const char *ifname) {

 	}

 	*dp = '\0';

-	return open (devname, O_RDWR, 0);

+	return open (devname, O_RDWR | O_CLOEXEC, 0);

 }

 /*

diff -up dhcp-4.3.3b1/common/nit.c.cloexec dhcp-4.3.3b1/common/nit.c

--- dhcp-4.3.3b1/common/nit.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/common/nit.c	2015-08-10 10:46:20.275755506 +0200

@@ -75,7 +75,7 @@ int if_register_nit (info)

 	struct strioctl sio;

 	/* Open a NIT device */

-	sock = open ("/dev/nit", O_RDWR);

+	sock = open ("/dev/nit", O_RDWR | O_CLOEXEC);

 	if (sock < 0)

 		log_fatal ("Can't open NIT device for %s: %m", info -> name);

diff -up dhcp-4.3.3b1/common/resolv.c.cloexec dhcp-4.3.3b1/common/resolv.c

--- dhcp-4.3.3b1/common/resolv.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/common/resolv.c	2015-08-10 10:46:20.276755503 +0200

@@ -44,7 +44,7 @@ void read_resolv_conf (parse_time)

 	struct domain_search_list *dp, *dl, *nd;

 	isc_result_t status;

-	if ((file = open (path_resolv_conf, O_RDONLY)) < 0) {

+	if ((file = open (path_resolv_conf, O_RDONLY | O_CLOEXEC)) < 0) {

 		log_error ("Can't open %s: %m", path_resolv_conf);

 		return;

 	}

diff -up dhcp-4.3.3b1/common/upf.c.cloexec dhcp-4.3.3b1/common/upf.c

--- dhcp-4.3.3b1/common/upf.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/common/upf.c	2015-08-10 10:46:20.276755503 +0200

@@ -71,7 +71,7 @@ int if_register_upf (info)

 		/* %Audit% Cannot exceed 36 bytes. %2004.06.17,Safe% */

 		sprintf(filename, "/dev/pf/pfilt%d", b);

-		sock = open (filename, O_RDWR, 0);

+		sock = open (filename, O_RDWR | O_CLOEXEC, 0);

 		if (sock < 0) {

 			if (errno == EBUSY) {

 				continue;

diff -up dhcp-4.3.3b1/omapip/trace.c.cloexec dhcp-4.3.3b1/omapip/trace.c

--- dhcp-4.3.3b1/omapip/trace.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/omapip/trace.c	2015-08-10 10:46:20.276755503 +0200

@@ -138,10 +138,10 @@ isc_result_t trace_begin (const char *fi

 		return DHCP_R_INVALIDARG;

 	}

-	traceoutfile = open (filename, O_CREAT | O_WRONLY | O_EXCL, 0600);

+	traceoutfile = open (filename, O_CREAT | O_WRONLY | O_EXCL | O_CLOEXEC, 0600);

 	if (traceoutfile < 0 && errno == EEXIST) {

 		log_error ("WARNING: Overwriting trace file \"%s\"", filename);

-		traceoutfile = open (filename, O_WRONLY | O_EXCL | O_TRUNC,

+		traceoutfile = open (filename, O_WRONLY | O_EXCL | O_TRUNC | O_CLOEXEC,

 				     0600);

 	}

@@ -429,7 +429,7 @@ void trace_file_replay (const char *file

 	isc_result_t result;

 	int len;

-	traceinfile = fopen (filename, "r");

+	traceinfile = fopen (filename, "re");

 	if (!traceinfile) {

 		log_error("Can't open tracefile %s: %m", filename);

 		return;

diff -up dhcp-4.3.3b1/relay/dhcrelay.c.cloexec dhcp-4.3.3b1/relay/dhcrelay.c

--- dhcp-4.3.3b1/relay/dhcrelay.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/relay/dhcrelay.c	2015-08-10 10:46:20.276755503 +0200

@@ -187,11 +187,11 @@ main(int argc, char **argv) {

 	/* Make sure that file descriptors 0(stdin), 1,(stdout), and

 	   2(stderr) are open. To do this, we assume that when we

 	   open a file the lowest available file descriptor is used. */

-	fd = open("/dev/null", O_RDWR);

+	fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 0)

-		fd = open("/dev/null", O_RDWR);

+		fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 1)

-		fd = open("/dev/null", O_RDWR);

+		fd = open("/dev/null", O_RDWR | O_CLOEXEC);

 	if (fd == 2)

 		log_perror = 0; /* No sense logging to /dev/null. */

 	else if (fd != -1)

@@ -558,13 +558,13 @@ main(int argc, char **argv) {

 		if (no_pid_file == ISC_FALSE) {

 			pfdesc = open(path_dhcrelay_pid,

-				      O_CREAT | O_TRUNC | O_WRONLY, 0644);

+				      O_CREAT | O_TRUNC | O_WRONLY | O_CLOEXEC, 0644);

 			if (pfdesc < 0) {

 				log_error("Can't create %s: %m",

 					  path_dhcrelay_pid);

 			} else {

-				pf = fdopen(pfdesc, "w");

+				pf = fdopen(pfdesc, "we");

 				if (!pf)

 					log_error("Can't fdopen %s: %m",

 						  path_dhcrelay_pid);

diff -up dhcp-4.3.3b1/server/confpars.c.cloexec dhcp-4.3.3b1/server/confpars.c

--- dhcp-4.3.3b1/server/confpars.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/server/confpars.c	2015-08-10 10:46:20.277755500 +0200

@@ -111,7 +111,7 @@ isc_result_t read_conf_file (const char

 	}

 #endif

-	if ((file = open (filename, O_RDONLY)) < 0) {

+	if ((file = open (filename, O_RDONLY | O_CLOEXEC)) < 0) {

 		if (leasep) {

 			log_error ("Can't open lease database %s: %m --",

 				   path_dhcpd_db);

diff -up dhcp-4.3.3b1/server/db.c.cloexec dhcp-4.3.3b1/server/db.c

--- dhcp-4.3.3b1/server/db.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/server/db.c	2015-08-10 10:47:32.644518358 +0200

@@ -1072,7 +1072,7 @@ void db_startup (testp)

 	}

 #endif

 	if (!testp) {

-		db_file = fopen (path_dhcpd_db, "a");

+		db_file = fopen (path_dhcpd_db, "ae");

 		if (!db_file)

 			log_fatal ("Can't open %s for append.", path_dhcpd_db);

 		expire_all_pools ();

@@ -1120,7 +1120,7 @@ int new_lease_file ()

 		     path_dhcpd_db, (int)t) >= sizeof newfname)

 		log_fatal("new_lease_file: lease file path too long");

-	db_fd = open (newfname, O_WRONLY | O_TRUNC | O_CREAT, 0664);

+	db_fd = open (newfname, O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, 0664);

 	if (db_fd < 0) {

 		log_error ("Can't create new lease file: %m");

 		return 0;

@@ -1141,7 +1141,7 @@ int new_lease_file ()

 	}

 #endif /* PARANOIA */

-	if ((new_db_file = fdopen(db_fd, "w")) == NULL) {

+	if ((new_db_file = fdopen(db_fd, "we")) == NULL) {

 		log_error("Can't fdopen new lease file: %m");

 		close(db_fd);

 		goto fdfail;

diff -up dhcp-4.3.3b1/server/dhcpd.c.cloexec dhcp-4.3.3b1/server/dhcpd.c

--- dhcp-4.3.3b1/server/dhcpd.c.cloexec	2015-07-30 15:17:16.000000000 +0200

+++ dhcp-4.3.3b1/server/dhcpd.c	2015-08-10 10:46:20.278755497 +0200

@@ -194,11 +194,11 @@ main(int argc, char **argv) {

         /* Make sure that file descriptors 0 (stdin), 1, (stdout), and

            2 (stderr) are open. To do this, we assume that when we

            open a file the lowest available file descriptor is used. */

-        fd = open("/dev/null", O_RDWR);

+        fd = open("/dev/null", O_RDWR | O_CLOEXEC);

         if (fd == 0)

-                fd = open("/dev/null", O_RDWR);

+                fd = open("/dev/null", O_RDWR | O_CLOEXEC);

         if (fd == 1)

-                fd = open("/dev/null", O_RDWR);

+                fd = open("/dev/null", O_RDWR | O_CLOEXEC);

         if (fd == 2)

                 log_perror = 0; /* No sense logging to /dev/null. */

         else if (fd != -1)

@@ -743,7 +743,7 @@ main(int argc, char **argv) {

 	 * appropriate.

 	 */

 	if (no_pid_file == ISC_FALSE) {

-		i = open(path_dhcpd_pid, O_WRONLY|O_CREAT|O_TRUNC, 0644);

+		i = open(path_dhcpd_pid, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0644);

 		if (i >= 0) {

 			sprintf(pbuf, "%d\n", (int) getpid());

 			IGNORE_RET(write(i, pbuf, strlen(pbuf)));

@@ -787,9 +787,9 @@ main(int argc, char **argv) {

                 (void) close(2);

                 /* Reopen them on /dev/null. */

-                (void) open("/dev/null", O_RDWR);

-                (void) open("/dev/null", O_RDWR);

-                (void) open("/dev/null", O_RDWR);

+                (void) open("/dev/null", O_RDWR | O_CLOEXEC);

+                (void) open("/dev/null", O_RDWR | O_CLOEXEC);

+                (void) open("/dev/null", O_RDWR | O_CLOEXEC);

                 log_perror = 0; /* No sense logging to /dev/null. */

        		IGNORE_RET (chdir("/"));

diff -up dhcp-4.3.3b1/server/ldap.c.cloexec dhcp-4.3.3b1/server/ldap.c

--- dhcp-4.3.3b1/server/ldap.c.cloexec	2015-07-30 21:03:40.000000000 +0200

+++ dhcp-4.3.3b1/server/ldap.c	2015-08-10 10:46:20.279755493 +0200

@@ -1442,7 +1442,7 @@ ldap_start (void)

   if (ldap_debug_file != NULL && ldap_debug_fd == -1)

     {

-      if ((ldap_debug_fd = open (ldap_debug_file, O_CREAT | O_TRUNC | O_WRONLY,

+      if ((ldap_debug_fd = open (ldap_debug_file, O_CREAT | O_TRUNC | O_WRONLY | O_CLOEXEC,

                                  S_IRUSR | S_IWUSR)) < 0)

         log_error ("Error opening debug LDAP log file %s: %s", ldap_debug_file,

                    strerror (errno));