From: Breno Leitao <leitao@debian.org>
Date: Tue, 15 Apr 2025 19:28:56 +0000 (-0700)
Subject: ipv4: Use nlmsg_payload in fib_frontend file
X-Git-Tag: v6.16-rc1~132^2~280^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b411638fb92509a518506cbf0bbce8a8a3bd07fb;p=thirdparty%2Fkernel%2Fstable.git

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 3f4e629998fab..57f088e5540e2 100644
--- 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");