if: Don't use a variable length buffer

Otherwise SSP complains.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/if.c b/src/if.c
index 75776512..2fa6e133 100644
--- a/src/if.c
+++ b/src/if.c
@@ -183,14 +183,18 @@ if_randomisemac(struct interface *ifp)
 {
 	uint32_t randnum;
 	size_t hwlen = ifp->hwlen, rlen = 0;
-	uint8_t buf[hwlen], *bp = buf, *rp = (uint8_t *)&randnum;
-	char sbuf[hwlen * 3];
+	uint8_t buf[HWADDR_LEN], *bp = buf, *rp = (uint8_t *)&randnum;
+	char sbuf[HWADDR_LEN * 3];
 	int retval;
 
 	if (hwlen == 0) {
 		errno = ENOTSUP;
 		return -1;
 	}
+	if (hwlen > sizeof(buf)) {
+		errno = ENOBUFS;
+		return -1;
+	}
 
 	for (; hwlen != 0; hwlen--) {
 		if (rlen == 0) {