Add secure gethostname() wrapper

gethostname() func does not ensure null-terminated string
if hostname is longer than buffer length.
For security, a function s_gethostname() has been added
to ensure that "\0" is added to the end of the buffer.
Previously this had to be handled in each place
of the gethostname() call.

Signed-off-by: Blazej Kucman <blazej.kucman@intel.com>
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/mdadm.c b/mdadm.c
index 076b45e0..e32598cb 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -1340,8 +1340,7 @@ int main(int argc, char *argv[])
 	if (c.homehost == NULL && c.require_homehost)
 		c.homehost = conf_get_homehost(&c.require_homehost);
 	if (c.homehost == NULL || strcasecmp(c.homehost, "<system>") == 0) {
-		if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
-			sys_hostname[sizeof(sys_hostname)-1] = 0;
+		if (s_gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
 			c.homehost = sys_hostname;
 		}
 	}