--- a/sys/kern/kern_environment.c	2026-06-29 12:51:19.000000000 +0000
+++ b/sys/kern/kern_environment.c	2026-10-26 00:25:42.777043079 +0000
@@ -161,7 +161,11 @@
 			kfree(value, M_TEMP);
 			goto done;
 		}
-		ksetenv(name, value);
+		if (ksetenv(name, value) < 0) {
+			kfree(value, M_TEMP);
+			error = EINVAL;
+			goto done;
+		}
 		kfree(value, M_TEMP);
 		break;
 	case KENV_UNSET: