qcacld-3.0: Validate he operation info before nla put

Currenly when driver receives get station info command in
in sta mode, he operation information is also copied to the
response buffer. Host does not validate he operation info
and tries to do nla put which is leading to NULL pointer
dereference.

To address above issue, add a check to validate the he operation
info before nla put operation.

Change-Id: Iaa093e4d4e3a9cec978f16c69a66c778b2dcf79f
CRs-Fixed: 2676773

core/hdd/src/wlan_hdd_station_info.c

@@ -591,6 +591,10 @@ static int32_t hdd_add_he_oper_info(
 {
 	int32_t ret = 0;
 
+	if (!hdd_sta_ctx->cache_conn_info.he_oper_len ||
+	    !hdd_sta_ctx->cache_conn_info.he_operation)
+		return ret;
+
 	if (nla_put(skb, HE_OPERATION,
 		    hdd_sta_ctx->cache_conn_info.he_oper_len,
 		     hdd_sta_ctx->cache_conn_info.he_operation))