commit 358664cc6d1b5f7c36004be0179b36011b81c49d
author Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Mon Sep 20 14:11:19 2010 +0100
committer Blue Swirl <blauwirbel@gmail.com> Sun Oct 03 06:43:10 2010 +0000
tree e4ed0b46de41e0bd7f7bc515a1562df6fd5f5737
parent 7fd3f494409775b491ca08f9026c45da13852a6d

console: Avoid dereferencing NULL active_console

The console_select() function does not check that active_console is
non-NULL before dereferencing it.  When invoked with qemu -nodefaults it
is possible to hit this case.

This patch checks that active_console is non-NULL before stashing away
the old console dimensions in console_select().

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

console.c

diff --git a/console.c b/console.c
index 698bc10..c1728b1 100644
--- a/console.c
+++ b/console.c
@@ -1060,8 +1060,10 @@
 
     if (index >= MAX_CONSOLES)
         return;
-    active_console->g_width = ds_get_width(active_console->ds);
-    active_console->g_height = ds_get_height(active_console->ds);
+    if (active_console) {
+        active_console->g_width = ds_get_width(active_console->ds);
+        active_console->g_height = ds_get_height(active_console->ds);
+    }
     s = consoles[index];
     if (s) {
         DisplayState *ds = s->ds;