From: Breno Leitao <leitao@debian.org>
Date: Tue, 15 Apr 2025 19:28:58 +0000 (-0700)
Subject: ipv4: Use nlmsg_payload in ipmr file
X-Git-Tag: v6.16-rc1~132^2~280^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=04e00a849e7c25b331f103bf71a56fd078f73f8d;p=thirdparty%2Flinux.git

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 a8b04d4abcaae..3b5677d8467ef 100644
--- 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");