[ovs-dev] [PATCH 14/14] datapath-windows: Fix potential crash in OvsInitConfiguredSwitchNics: virtPort

[Samuel Ghinet]

If the hyper-v switch port type is external, then the function
OvsInitConfiguredSwitchNics allocates a vport, and if allocation
succeeds, it procedes with the initialization. However, at this
point, virtPort may happen to be null, but check against virtPort
was not made - this means that if virtPort was null, later on its
fields would try to be accessed.

This patch adds a check for virtPort as well, so that the fields of
virtPort will not be accessed if virtPort is NULL.

Signed-off-by: Samuel Ghinet <sghinet at cloudbasesolutions.com>
---
 datapath-windows/ovsext/Vport.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/datapath-windows/ovsext/Vport.c b/datapath-windows/ovsext/Vport.c
index d90fd2b..1e05d60 100644
--- a/datapath-windows/ovsext/Vport.c
+++ b/datapath-windows/ovsext/Vport.c
@@ -857,10 +857,9 @@ OvsInitConfiguredSwitchNics(POVS_SWITCH_CONTEXT switchContext)
 
         if (nicParam->NicType == NdisSwitchNicTypeExternal &&
             nicParam->NicIndex != 0) {
-            POVS_VPORT_ENTRY virtVport =
-                   (POVS_VPORT_ENTRY)switchContext->externalVport;
+            POVS_VPORT_ENTRY virtVport = switchContext->externalVport;
             vport = OvsAllocateVport();
-            if (vport) {
+            if (vport && virtVport) {
                 OvsInitPhysNicVport(vport, virtVport, nicParam->NicIndex);
                 status = OvsInitVportCommon(switchContext, vport);
                 if (status != NDIS_STATUS_SUCCESS) {
-- 
1.8.3.msysgit.0