From: Breno Leitao <leitao@debian.org>
Date: Thu, 17 Apr 2025 13:03:07 +0000 (-0700)
Subject: net: Use nlmsg_payload in neighbour file
X-Git-Tag: v6.16-rc1~132^2~258^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9929ba194299eadc80849db4cb992f4bc310401b;p=thirdparty%2Flinux.git

net: Use nlmsg_payload in neighbour 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/20250417-nlmsg_v3-v1-1-9b09d9d7e61d@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 65cf582b5dacd..254067b719da3 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2747,12 +2747,12 @@ static int neigh_valid_dump_req(const struct nlmsghdr *nlh,
 	if (strict_check) {
 		struct ndmsg *ndm;
 
-		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
+		ndm = nlmsg_payload(nlh, sizeof(*ndm));
+		if (!ndm) {
 			NL_SET_ERR_MSG(extack, "Invalid header for neighbor dump request");
 			return -EINVAL;
 		}
 
-		ndm = nlmsg_data(nlh);
 		if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_ifindex ||
 		    ndm->ndm_state || ndm->ndm_type) {
 			NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor dump request");