From: Stephen Hemminger <stephen@networkplumber.org>
Date: Wed, 23 May 2018 18:02:00 -0700
Patch-mainline: v4.18-rc1
Subject: hv_netvsc: fix bogus ifalias on network device
Git-commit: d97cde6ab547a8115fb4fae73f030a96519ac3c6
References: bsc#1107207
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 <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Olaf Hering <ohering@suse.de>
---
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
--- 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));