Index: /trunk/src/VBox/Devices/Network/slirp/debug.c
===================================================================
--- /trunk/src/VBox/Devices/Network/slirp/debug.c	(revision 37936)
+++ /trunk/src/VBox/Devices/Network/slirp/debug.c	(revision 37937)
@@ -299,7 +299,14 @@
     const struct tcpcb *tp = (const struct tcpcb *)pvValue;
     AssertReturn(RTStrCmp(pszType, "tcpcb793") == 0 && tp, 0);
-    cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0, "TCB793[ state:%R[tcpstate] SND(UNA: %x, NXT: %x, UP: %x, WND: %x, WL1:%x, WL2:%x, ISS:%x), ",
-                      tp->t_state, tp->snd_una, tp->snd_nxt, tp->snd_up, tp->snd_wnd, tp->snd_wl1, tp->snd_wl2, tp->iss);
-    cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0, "RCV(WND: %x, NXT: %x, UP: %x, IRS:%x)]", tp->rcv_wnd, tp->rcv_nxt, tp->rcv_up, tp->irs);
+    if (tp)
+    {
+        cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0, "TCB793[ state:%R[tcpstate] SND(UNA: %x, NXT: %x, UP: %x, WND: %x, WL1:%x, WL2:%x, ISS:%x), ",
+                          tp->t_state, tp->snd_una, tp->snd_nxt, tp->snd_up, tp->snd_wnd, tp->snd_wl1, tp->snd_wl2, tp->iss);
+        cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0, "RCV(WND: %x, NXT: %x, UP: %x, IRS:%x)]", tp->rcv_wnd, tp->rcv_nxt, tp->rcv_up, tp->irs);
+    }
+    else
+    {
+        cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0, "TCB793[ NULL ]");
+    }
     return cb;
 }