From 162b394726bbf3198034aa9aa5361f1256641e3e Mon Sep 17 00:00:00 2001
From: Joachim Nilsson <troglobit@gmail.com>
Date: Sun, 21 Jun 2015 21:54:24 +0200
Subject: [PATCH] Replace insecure tmpfile() with mkstemp() based local
 tempfile()

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
---
 exec.c    |  2 +-
 helpers.c | 21 +++++++++++++++++++++
 helpers.h |  2 ++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/exec.c b/exec.c
index 6bfb8138..d6d74a1e 100644
--- a/exec.c
+++ b/exec.c
@@ -179,7 +179,7 @@ int run_interactive(char *cmd, char *fmt, ...)
 	}
 
 	/* Redirect output from cmd to a tempfile */
-	fp = tmpfile();
+	fp = tempfile();
 	if (fp && !debug) {
 		oldout = dup(STDOUT_FILENO);
 		olderr = dup(STDERR_FILENO);
diff --git a/helpers.c b/helpers.c
index 7757eab8..16525f63 100644
--- a/helpers.c
+++ b/helpers.c
@@ -126,6 +126,27 @@ int atonum(char *str)
 	return val;
 }
 
+/**
+ * tempfile - A secure tmpfile() replacement
+ *
+ * This is the secure replacement for tmpfile() that does not exist in GLIBC.
+ * The function uses mkstemp() for security.
+ *
+ * Returns:
+ * An open %FILE pointer, or %NULL on error.
+ */
+FILE *tempfile(void)
+{
+	int fd;
+	char *template = "/tmp/finit.XXXXXX";
+
+	fd = mkstemp(template);
+	if (-1 == fd)
+		return NULL;
+
+	return fdopen(fd, "rw");
+}
+
 static int encode(int lvl)
 {
 	if (!lvl) return 0;
diff --git a/helpers.h b/helpers.h
index 122b9c92..9d374d90 100644
--- a/helpers.h
+++ b/helpers.h
@@ -69,6 +69,8 @@ int     makepath        (char *path);
 void    ifconfig        (char *ifname, char *addr, char *mask, int up);
 
 int     atonum          (char *str);
+FILE   *tempfile        (void);
+
 void    runlevel_set    (int pre, int now);
 int     runlevel_get    (void);
 char   *runlevel_string (int levels);