main/qemu/0428-cirrus-don-t-overflow-CirrusVGAState-cirrus_bltbuf.patch


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From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 19 Nov 2014 13:27:28 +0100
Subject: [PATCH] cirrus: don't overflow CirrusVGAState->cirrus_bltbuf

This is CVE-2014-8106.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit bf25983345ca44aec3dd92c57142be45452bd38a)
---
 hw/display/cirrus_vga.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 64e489e..f16960b 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;