From: Prasad J Pandit <address@hidden>

RTL8139 ethernet controller in C+ mode supports multiple
descriptor rings, each with maximum of 64 descriptors. While
processing transmit descriptor ring in 'rtl8139_cplus_transmit',
it does not limit the descriptor count and runs forever. Add
check to avoid it.

Reported-by: Andrew Henderson <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
 hw/net/rtl8139.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 3345bc6..f05e59c 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -2350,7 +2350,7 @@ static void rtl8139_cplus_transmit(RTL8139State *s)
 {
     int txcount = 0;
 
-    while (rtl8139_cplus_transmit_one(s))
+    while (txcount < 64 && rtl8139_cplus_transmit_one(s))
     {
         ++txcount;
     }
-- 
2.7.4