Monitor: use devname as char array instead of pointer

Device name wasn't filled properly due to incorrect use of strcpy.
Strcpy was used twice. Firstly to fill devname with "/dev/md/"
and then to add chosen name. First strcpy result was overwritten by
second one (as a result <device_name> instead of "/dev/md/<device_name>"
was assigned). This commit changes this implementation to use snprintf
and devname with fixed size.

Signed-off-by: Kinga Tanska <kinga.tanska@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/Monitor.c b/Monitor.c
index 6ca1ebe5..a5b11ae2 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -190,9 +190,11 @@ int Monitor(struct mddev_dev *devlist,
 			if (mdlist->devname[0] == '/')
 				st->devname = xstrdup(mdlist->devname);
 			else {
-				st->devname = xmalloc(8+strlen(mdlist->devname)+1);
-				strcpy(strcpy(st->devname, "/dev/md/"),
-				       mdlist->devname);
+				/* length of "/dev/md/" + device name + terminating byte */
+				size_t _len = sizeof("/dev/md/") + strnlen(mdlist->devname, PATH_MAX);
+
+				st->devname = xcalloc(_len, sizeof(char));
+				snprintf(st->devname, _len, "/dev/md/%s", mdlist->devname);
 			}
 			if (!is_mddev(mdlist->devname))
 				return 1;