From: Jiri Pirko <jiri@mellanox.com>
Date: Sat, 5 Oct 2019 20:04:40 +0200
Subject: net: tipc: allocate attrs locally instead of using
 genl_family_attrbuf in compat_dumpit()
Patch-mainline: v5.5-rc1
Git-commit: c6c08614eb32d250612c9d2940e48951fb4ba325
References: bsc#1154353

As this is the last user of genl_family_attrbuf, convert to allocate
attrs locally and do it in a similar way this is done in compat_doit().

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/tipc/netlink.c        |   12 ------------
 net/tipc/netlink.h        |    1 -
 net/tipc/netlink_compat.c |   19 +++++++++++++++----
 3 files changed, 15 insertions(+), 17 deletions(-)

--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -271,18 +271,6 @@ struct genl_family tipc_genl_family __ro
 	.n_ops		= ARRAY_SIZE(tipc_genl_v2_ops),
 };
 
-int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***attr)
-{
-	u32 maxattr = tipc_genl_family.maxattr;
-
-	*attr = genl_family_attrbuf(&tipc_genl_family);
-	if (!*attr)
-		return -EOPNOTSUPP;
-
-	return nlmsg_parse_deprecated(nlh, GENL_HDRLEN, *attr, maxattr,
-				      tipc_nl_policy, NULL);
-}
-
 int __init tipc_netlink_start(void)
 {
 	int res;
--- a/net/tipc/netlink.h
+++ b/net/tipc/netlink.h
@@ -38,7 +38,6 @@
 #include <net/netlink.h>
 
 extern struct genl_family tipc_genl_family;
-int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***buf);
 
 struct tipc_nl_msg {
 	struct sk_buff *skb;
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -186,6 +186,7 @@ static int __tipc_nl_compat_dumpit(struc
 	struct sk_buff *buf;
 	struct nlmsghdr *nlmsg;
 	struct netlink_callback cb;
+	struct nlattr **attrbuf;
 
 	memset(&cb, 0, sizeof(cb));
 	cb.nlh = (struct nlmsghdr *)arg->data;
@@ -201,19 +202,28 @@ static int __tipc_nl_compat_dumpit(struc
 		return -ENOMEM;
 	}
 
+	attrbuf = kmalloc_array(tipc_genl_family.maxattr + 1,
+				sizeof(struct nlattr *), GFP_KERNEL);
+	if (!attrbuf) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
 	do {
 		int rem;
 
 		len = (*cmd->dumpit)(buf, &cb);
 
 		nlmsg_for_each_msg(nlmsg, nlmsg_hdr(buf), len, rem) {
-			struct nlattr **attrs;
-
-			err = tipc_nlmsg_parse(nlmsg, &attrs);
+			err = nlmsg_parse_deprecated(nlmsg, GENL_HDRLEN,
+						     attrbuf,
+						     tipc_genl_family.maxattr,
+						     tipc_genl_family.policy,
+						     NULL);
 			if (err)
 				goto err_out;
 
-			err = (*cmd->format)(msg, attrs);
+			err = (*cmd->format)(msg, attrbuf);
 			if (err)
 				goto err_out;
 
@@ -231,6 +241,7 @@ static int __tipc_nl_compat_dumpit(struc
 	err = 0;
 
 err_out:
+	kfree(attrbuf);
 	tipc_dump_done(&cb);
 	kfree_skb(buf);