libndp: fix [cppcheck] Undefined behavior: Variable 'buf' is used as parameter and destination in s[n]printf()

cppcheck --enable=all --inconclusive --std=posix .

ndp_msg_opt_dnssl_domain():
			if (dom_len > len)
				return NULL;

			if (strlen(buf))
---->				sprintf(buf, "%s.", buf);
			buf[strlen(buf) + dom_len] = '\0';
			memcpy(buf + strlen(buf), ptr, dom_len);

So just use strcat instead.

Reported-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>

1 files changed, 1 insertions, 1 deletions

diff --git a/libndp/libndp.c b/libndp/libndp.c
index 0bc3fe3..e510e2e 100644
--- a/libndp/libndp.c
+++ b/libndp/libndp.c
@@ -1540,7 +1540,7 @@ char *ndp_msg_opt_dnssl_domain(struct ndp_msg *msg, int offset,
 				return NULL;
 
 			if (strlen(buf))
-				sprintf(buf, "%s.", buf);
+				strcat(buf, ".");
 			buf[strlen(buf) + dom_len] = '\0';
 			memcpy(buf + strlen(buf), ptr, dom_len);
 			ptr += dom_len;