From: Breno Leitao <leitao@debian.org>
Date: Tue, 15 Apr 2025 19:28:53 +0000 (-0700)
Subject: ipv6: Use nlmsg_payload in addrconf file
X-Git-Tag: v6.16-rc1~132^2~280^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6c454270a8511280ba5981e57e3bcb3c1408ebfa;p=thirdparty%2Fkernel%2Fstable.git

ipv6: Use nlmsg_payload in addrconf 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-v1-2-a1c75d493fd7@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4af2761795428..ec6c4ca6d6d99 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6112,7 +6112,8 @@ static int inet6_valid_dump_ifinfo(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_MOD(extack, "Invalid header for link dump request");
 		return -EINVAL;
 	}
@@ -6122,7 +6123,6 @@ static int inet6_valid_dump_ifinfo(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_MOD(extack, "Invalid values in header for dump request");