ipv4: Use nlmsg_payload in fib_frontend file

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/20250415-nlmsg_v2-v1-5-a1c75d493fd7@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 3f4e629998fab4e2ae241c7efe40d9d162f8f517..57f088e5540e2b9c03a191b06ba5e87a46f13abe 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -948,12 +948,12 @@ int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
        if (filter->rtnl_held)
                ASSERT_RTNL();
 
-       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+       rtm = nlmsg_payload(nlh, sizeof(*rtm));
+       if (!rtm) {
                NL_SET_ERR_MSG(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_scope) {
                NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");