[Qemu-devel] [PATCH 4/4] vnc: Limit r/w access to size of allocated memory

[Corentin Chary <corentin.chary@gmail.com>]

From: Stefan Weil <weil@mail.berlios.de>

This fixes memory reads and writes which exceeded the upper limit
of allocated memory vd->guest.ds->data and vd->server->data.

Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
---
 ui/vnc.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 90b6384..3138053 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2414,6 +2414,9 @@ static int vnc_refresh_server_surface(VncDisplay *vd)
      * Update server dirty map.
      */
     cmp_bytes = 16 * ds_get_bytes_per_pixel(vd->ds);
+    if (cmp_bytes > vd->ds->surface->linesize) {
+        cmp_bytes = vd->ds->surface->linesize;
+    }
     guest_row  = vd->guest.ds->data;
     server_row = vd->server->data;
     for (y = 0; y < vd->guest.ds->height; y++) {
-- 
1.7.3.4