diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 44abc52bae1360..9d144cbd4e62a3 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -979,6 +979,8 @@ fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg)
 			if (val == TCP_CA_UNSPEC)
 				return -EINVAL;
 		} else {
+			if (nla_len(nla) != sizeof(u32))
+				return false;
 			val = nla_get_u32(nla);
 		}
 		if (type == RTAX_ADVMSS && val > 65535 - 40)