From: David Ahern <dsahern@gmail.com>
Date: Mon, 8 Oct 2018 03:16:23 +0000 (-0700)
Subject: netlink: Add extack message to nlmsg_parse for invalid header length
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3d0d4337d7a105c5e8ba85c6e7b75437b4c6745e;p=linux.git

netlink: Add extack message to nlmsg_parse for invalid header length

Give a user a reason why EINVAL is returned in nlmsg_parse.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 589683091f167..9522a0bf1f3af 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -516,8 +516,10 @@ static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
 			      const struct nla_policy *policy,
 			      struct netlink_ext_ack *extack)
 {
-	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
+		NL_SET_ERR_MSG(extack, "Invalid header length");
 		return -EINVAL;
+	}
 
 	return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
 			 nlmsg_attrlen(nlh, hdrlen), policy, extack);