diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -973,9 +973,16 @@
 		case CAPFAIL_PROTO:
 			kcd->cap_int = *(const int *)data;
 			break;
-		case CAPFAIL_SOCKADDR:
-			kcd->cap_sockaddr = *(const struct sockaddr *)data;
+		case CAPFAIL_SOCKADDR: {
+			size_t len;
+
+			len = MIN(((const struct sockaddr *)data)->sa_len,
+			    sizeof(kcd->cap_sockaddr));
+			memset(&kcd->cap_sockaddr, 0,
+			    sizeof(kcd->cap_sockaddr));
+			memcpy(&kcd->cap_sockaddr, data, len);
 			break;
+		}
 		case CAPFAIL_NAMEI:
 			strlcpy(kcd->cap_path, data, MAXPATHLEN);
 			break;