From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH net-next] hv_netvsc: fix bogus ifalias on network device Date: Wed, 23 May 2018 18:02:00 -0700 Message-ID: <20180524010200.11722-1-sthemmin@microsoft.com> Cc: Stephen Hemminger To: netdev@vger.kernel.org Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:39963 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935260AbeEXBCE (ORCPT ); Wed, 23 May 2018 21:02:04 -0400 Received: by mail-pg0-f68.google.com with SMTP id l2-v6so10160435pgc.7 for ; Wed, 23 May 2018 18:02:04 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: If the guest network adapter is not configured with DeviceNaming enabled on the host, then the query for friendly name will return success but with a zero length name. Which then leads to a garbage value (stack contents) for ifalias. Fix is simple, just don't set name if host doesn't return it. Fixes: 0fe554a46a0f ("hv_netvsc: propogate Hyper-V friendly name into interface alias") Signed-off-by: Stephen Hemminger --- drivers/net/hyperv/rndis_filter.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index 7f3dab4b4cbc..5428bb261102 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -1237,7 +1237,10 @@ static void rndis_get_friendly_name(struct net_device *net, if (rndis_filter_query_device(rndis_device, net_device, RNDIS_OID_GEN_FRIENDLY_NAME, wname, &size) != 0) - return; + return; /* ignore if host does not support */ + + if (size == 0) + return; /* name not set */ /* Convert Windows Unicode string to UTF-8 */ len = ucs2_as_utf8(ifalias, wname, sizeof(ifalias)); -- 2.17.0