From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 19 Nov 2014 12:27:28 +0000 (+0100)
Subject: cirrus: don't overflow CirrusVGAState->cirrus_bltbuf
X-Git-Tag: qemu-xen-4.5.1-rc1~1
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0b8fb1ec3d666d1eb8bbff56c76c5e6daa2789e4;p=qemu-xen.git

cirrus: don't overflow CirrusVGAState->cirrus_bltbuf

This is CVE-2014-8106.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---

diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 757ab633b2..1a66fcf91d 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -292,6 +292,10 @@ static bool blit_is_unsafe(struct CirrusVGAState *s)
     assert(s->cirrus_blt_width > 0);
     assert(s->cirrus_blt_height > 0);
 
+    if (s->cirrus_blt_width > CIRRUS_BLTBUFSIZE) {
+        return true;
+    }
+
     if (blit_region_is_unsafe(s, s->cirrus_blt_dstpitch,
                               s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) {
         return true;