[PATCH 1/5] Check Fragment->Entry before calling RevokeForeignAccess

["Tu Dinh" <ngoc-tu.dinh@xxxxxxxxxx>]

Fragments of type XENVIF_TRANSMITTER_FRAGMENT_TYPE_MULTICAST_CONTROL do
not have a gnttab entry, and so we must check for that here.

Signed-off-by: Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx>
---
 src/xenvif/transmitter.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/xenvif/transmitter.c b/src/xenvif/transmitter.c
index 75b80f3..05a2002 100644
--- a/src/xenvif/transmitter.c
+++ b/src/xenvif/transmitter.c
@@ -1553,12 +1553,14 @@ __TransmitterRingUnprepareFragments(
         Fragment->Length = 0;
         Fragment->Offset = 0;
 
-        (VOID) XENBUS_GNTTAB(RevokeForeignAccess,
-                             &Transmitter->GnttabInterface,
-                             Ring->GnttabCache,
-                             TRUE,
-                             Fragment->Entry);
-        Fragment->Entry = NULL;
+        if (Fragment->Entry != NULL) {
+            (VOID) XENBUS_GNTTAB(RevokeForeignAccess,
+                                 &Transmitter->GnttabInterface,
+                                 Ring->GnttabCache,
+                                 TRUE,
+                                 Fragment->Entry);
+            Fragment->Entry = NULL;
+        }
 
         switch (Fragment->Type) {
         case XENVIF_TRANSMITTER_FRAGMENT_TYPE_BUFFER: {
-- 
2.53.0.windows.2



--
Ngoc Tu Dinh | Vates XCP-ng Developer

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