neighbour: Use nlmsg_payload in neightbl_valid_dump_info

Update neightbl_valid_dump_info function to utilize the new
nlmsg_payload() helper function.

This change improves code clarity and safety by ensuring that the
Netlink message payload is properly validated before accessing its data.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250414-nlmsg-v2-2-3d90cb42c6af@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a07249b59ae1e34b7772957cf6600c66646082b8..b6bc4836c6e453fa3d7c560560bcc0f47fbcf94b 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2430,12 +2430,12 @@ static int neightbl_valid_dump_info(const struct nlmsghdr *nlh,
 {
        struct ndtmsg *ndtm;
 
-       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndtm))) {
+       ndtm = nlmsg_payload(nlh, sizeof(*ndtm));
+       if (!ndtm) {
                NL_SET_ERR_MSG(extack, "Invalid header for neighbor table dump request");
                return -EINVAL;
        }
 
-       ndtm = nlmsg_data(nlh);
        if (ndtm->ndtm_pad1  || ndtm->ndtm_pad2) {
                NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor table dump request");
                return -EINVAL;