From: Lorenzo Colitti <lorenzo@google.com>
Date: Wed, 24 Aug 2016 06:46:25 +0000 (+0900)
Subject: net: diag: slightly refactor the inet_diag_bc_audit error checks.
X-Git-Tag: firefly_0821_release~176^2~174
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=e10225d940a6a5c4da393487129e4f0938f5402f;p=firefly-linux-kernel-4.4.55.git

net: diag: slightly refactor the inet_diag_bc_audit error checks.

This simplifies the code a bit and also allows inet_diag_bc_audit
to send to userspace an error that isn't EINVAL.

[cherry-pick of net-next 627cc4add53c0470bfd118002669205d222d3a54]

Change-Id: Iee3d2bbb19f3110d71f0698ffb293f9bdffc8ef1
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index e532671c3f4f..75f6d4bde273 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -687,10 +687,16 @@ static bool valid_port_comparison(const struct inet_diag_bc_op *op,
 	return true;
 }
 
-static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
+static int inet_diag_bc_audit(const struct nlattr *attr)
 {
-	const void *bc = bytecode;
-	int  len = bytecode_len;
+	const void *bytecode, *bc;
+	int bytecode_len, len;
+
+	if (!attr || nla_len(attr) < sizeof(struct inet_diag_bc_op))
+		return -EINVAL;
+
+	bytecode = bc = nla_data(attr);
+	len = bytecode_len = nla_len(attr);
 
 	while (len > 0) {
 		int min_len = sizeof(struct inet_diag_bc_op);
@@ -1001,13 +1007,13 @@ static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
 		if (nlmsg_attrlen(nlh, hdrlen)) {
 			struct nlattr *attr;
+			int err;
 
 			attr = nlmsg_find_attr(nlh, hdrlen,
 					       INET_DIAG_REQ_BYTECODE);
-			if (!attr ||
-			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
-			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
-				return -EINVAL;
+			err = inet_diag_bc_audit(attr);
+			if (err)
+				return err;
 		}
 		{
 			struct netlink_dump_control c = {
@@ -1032,13 +1038,13 @@ static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
 	    h->nlmsg_flags & NLM_F_DUMP) {
 		if (nlmsg_attrlen(h, hdrlen)) {
 			struct nlattr *attr;
+			int err;
 
 			attr = nlmsg_find_attr(h, hdrlen,
 					       INET_DIAG_REQ_BYTECODE);
-			if (!attr ||
-			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
-			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
-				return -EINVAL;
+			err = inet_diag_bc_audit(attr);
+			if (err)
+				return err;
 		}
 		{
 			struct netlink_dump_control c = {