[Qemu-devel] [PATCH] NetKVM: fix for indirectc mode when vring is full

[Ting Wang]

In function vring_add_indirect, there is no limiti
about free entry in vring. If vring is full,
vq->num_free will be less than zero, and
the address of vq->vring.desc becomes illegal.

Signed-off-by: Ting Wang <address@hidden>
---
 NetKVM/NDIS5/VirtIO/VirtIORing.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/NetKVM/NDIS5/VirtIO/VirtIORing.c b/NetKVM/NDIS5/VirtIO/VirtIORing.c
index 90ace4c..0f3783c 100644
--- a/NetKVM/NDIS5/VirtIO/VirtIORing.c
+++ b/NetKVM/NDIS5/VirtIO/VirtIORing.c
@@ -150,7 +150,7 @@ static int vring_add_buf(struct virtqueue *_vq,
         return -1;
     }
 
-    if (va_indirect)
+    if (va_indirect && (out + in) > 1 && vq->num_free)
     {
         int ret = vring_add_indirect(_vq, sg, out, in, va_indirect, 
phys_indirect);
         if (ret >= 0)
-- 
1.8.5