openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start

It seems that the intention of the code is to null check the value returned by function genlmsg_put. But the current code is null checking the address of the pointer that holds the value returned by genlmsg_put.

Fix this by properly null checking the value returned by function genlmsg_put in order to avoid a pontential null pointer dereference.

Addresses-Coverity-ID: 1461561 ("Dereference before null check")
Addresses-Coverity-ID: 1461562 ("Dereference null return value")

---
 net/openvswitch/meter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 2a5ba35..bc0b6fc 100644
@@ -106,7 +106,7 @@ ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
 	*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
 					info->snd_seq,
 					&dp_meter_genl_family, 0, cmd);
-	if (!ovs_reply_header) {
+	if (!*ovs_reply_header) {
 		nlmsg_free(skb);
 		return ERR_PTR(-EMSGSIZE);
 	}

2.7.4

From: "Gustavo A. R. Silva" <garsilva-L1vi/[email protected]>
Date: Tue, 14 Nov 2017 14:26:16 -0600

Applied.