ipv4: Use nlmsg_payload in route 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-v1-6-a1c75d493fd7@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 22dfc971aab4b69e859511157a60aa90826b2539..49cffbe838029567825e7ae664638228dc7f324a 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3205,7 +3205,8 @@ static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
        struct rtmsg *rtm;
        int i, err;
 
-       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+       rtm = nlmsg_payload(nlh, sizeof(*rtm));
+       if (!rtm) {
                NL_SET_ERR_MSG(extack,
                               "ipv4: Invalid header for route get request");
                return -EINVAL;
@@ -3215,7 +3216,6 @@ static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
                return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
                                              rtm_ipv4_policy, extack);
 
-       rtm = nlmsg_data(nlh);
        if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
            (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
            rtm->rtm_table || rtm->rtm_protocol ||