MFC r315199,r315200,r315203:

r315199:

sbin/dhclient: fix a memory leak in parse_client_lease_statement(..)

The memory stored by `lease` would have previously been leaked if an
unterminated lease declaration was found in an early-return code path.

CID:		1007114

r315200:

Fix -Wunused-but-set-warning with `ret`

While here, resolve Coverity warnings by demonstrating that vfprintf's
return value is being explicitly ignored.

Tested with:	clang, gcc 4.2.1, gcc 6.3.0

r315203:

sbin/dhclient: fix `vendor` storage leak in parse_option_decl(..)

This ensures the storage isn't leaked when non-NULL and the function
returns early, prior to the `free(vendor)` later on in the function.

CID:		1007111-1007113

2 files changed, 6 insertions, 3 deletions

diff --git a/sbin/dhclient/clparse.c b/sbin/dhclient/clparse.c
index 4f234c7..e735e33 100644
--- a/sbin/dhclient/clparse.c
+++ b/sbin/dhclient/clparse.c
@@ -510,6 +510,7 @@ parse_client_lease_statement(FILE *cfile, int is_static)
 		token = peek_token(&val, cfile);
 		if (token == EOF) {
 			parse_warn("unterminated lease declaration.");
+			free_client_lease(lease);
 			return;
 		}
 		if (token == RBRACE)
@@ -711,6 +712,7 @@ parse_option_decl(FILE *cfile, struct option_data *options)
 			parse_warn("expecting identifier after '.'");
 			if (token != SEMI)
 				skip_to_semi(cfile);
+			free(vendor);
 			return (NULL);
 		}
 
@@ -723,6 +725,7 @@ parse_option_decl(FILE *cfile, struct option_data *options)
 		if (!universe) {
 			parse_warn("no vendor named %s.", vendor);
 			skip_to_semi(cfile);
+			free(vendor);
 			return (NULL);
 		}
 	} else {
@@ -744,6 +747,7 @@ parse_option_decl(FILE *cfile, struct option_data *options)
 			parse_warn("no option named %s for vendor %s",
 				    val, vendor);
 		skip_to_semi(cfile);
+		free(vendor);
 		return (NULL);
 	}
 
diff --git a/sbin/dhclient/tests/fake.c b/sbin/dhclient/tests/fake.c
index c204d49..91bbc6e 100644
--- a/sbin/dhclient/tests/fake.c
+++ b/sbin/dhclient/tests/fake.c
@@ -14,7 +14,7 @@ error(char *fmt, ...)
 	va_list ap;
 
 	va_start(ap, fmt);
-	vfprintf(stderr, fmt, ap);
+	(void)vfprintf(stderr, fmt, ap);
 	va_end(ap);
 	fprintf(stderr, "\n");
 
@@ -24,11 +24,10 @@ error(char *fmt, ...)
 int
 warning(char *fmt, ...)
 {
-	int ret;
 	va_list ap;
 
 	va_start(ap, fmt);
-	ret = vfprintf(stderr, fmt, ap);
+	(void)vfprintf(stderr, fmt, ap);
 	va_end(ap);
 	fprintf(stderr, "\n");