ipv4: Use nlmsg_payload in ipmr 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-v1-7-a1c75d493fd7@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index a8b04d4abcaae87b6fcd538feaceab9b3e32792b..3b5677d8467ef022338d43cdb2a5a55fe03abdb3 100644 (file)
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -2511,7 +2511,8 @@ static int ipmr_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 multicast route get request");
                return -EINVAL;
        }
@@ -2520,7 +2521,6 @@ static int ipmr_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_tos || rtm->rtm_table || rtm->rtm_protocol ||
@@ -2836,7 +2836,8 @@ static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
 {
        struct ifinfomsg *ifm;
 
-       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
+       ifm = nlmsg_payload(nlh, sizeof(*ifm));
+       if (!ifm) {
                NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
                return -EINVAL;
        }
@@ -2846,7 +2847,6 @@ static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
                return -EINVAL;
        }
 
-       ifm = nlmsg_data(nlh);
        if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
            ifm->ifi_change || ifm->ifi_index) {
                NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");