mpls: Use nlmsg_payload in mpls_valid_fib_dump_req

Leverage the new nlmsg_payload() helper to avoid checking for message
size and then reading the nlmsg data.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250414-nlmsg-v2-5-3d90cb42c6af@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 1f63b32..bf7cd29 100644 (file)
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2095,12 +2095,12 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
        struct rtmsg *rtm;
        int err, i;
 
-       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+       rtm = nlmsg_payload(nlh, sizeof(*rtm));
+       if (!rtm) {
                NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
                return -EINVAL;
        }
 
-       rtm = nlmsg_data(nlh);
        if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
            rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
            rtm->rtm_flags) {