File 0203-fix-cirrus_vga-fix-OOB-read-case-qe.patch of Package qemu.19799

From: hangaohuai <hangaohuai@huawei.com>
Date: Tue, 14 Mar 2017 14:39:19 +0800
Subject: fix :cirrus_vga fix OOB read case qemu Segmentation fault

check the validity of parameters in cirrus_bitblt_rop_fwd_transp_xxx
and cirrus_bitblt_rop_fwd_xxx to avoid the OOB read which causes qemu Segmentation fault.

After the fix, we will touch the assert in
cirrus_invalidate_region:
assert(off_cur_end >= off_cur);

Signed-off-by: fangying <fangying1@huawei.com>
Signed-off-by: hangaohuai <hangaohuai@huawei.com>
Message-id: 20170314063919.16200-1-hangaohuai@huawei.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 215902d7b6fb50c6fc216fc74f770858278ed904)
[BR: BSC#1034908 CVE-2017-7718]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/display/cirrus_vga_rop.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/display/cirrus_vga_rop.h b/hw/display/cirrus_vga_rop.h
index 0925a009fefd958d4c893a5f4c99..b7447f8733fbd750424ba1e9d0cb 100644
--- a/hw/display/cirrus_vga_rop.h
+++ b/hw/display/cirrus_vga_rop.h
@@ -97,6 +97,11 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
     uint8_t p;
     dstpitch -= bltwidth;
     srcpitch -= bltwidth;
+
+    if (bltheight > 1 && (dstpitch < 0 || srcpitch < 0)) {
+        return;
+    }
+
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
 	    p = *dst;
@@ -143,6 +148,11 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
     uint8_t p1, p2;
     dstpitch -= bltwidth;
     srcpitch -= bltwidth;
+
+    if (bltheight > 1 && (dstpitch < 0 || srcpitch < 0)) {
+        return;
+    }
+
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x+=2) {
 	    p1 = *dst;