4f5da8
From 55c542cca671a5a130c44359c73d1e908353418e Mon Sep 17 00:00:00 2001
4f5da8
From: Gerd Hoffmann <kraxel@redhat.com>
4f5da8
Date: Tue, 7 Feb 2017 10:07:52 +0100
4f5da8
Subject: [PATCH 8/8] cirrus: fix oob access issue (CVE-2017-2615)
4f5da8
4f5da8
RH-Author: Gerd Hoffmann <kraxel@redhat.com>
4f5da8
Message-id: <1486462072-32174-8-git-send-email-kraxel@redhat.com>
4f5da8
Patchwork-id: 73565
4f5da8
O-Subject: [RHEL-7.4 qemu-kvm PATCH 7/7] cirrus: fix oob access issue (CVE-2017-2615)
4f5da8
Bugzilla: 1418232
4f5da8
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
4f5da8
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
4f5da8
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
4f5da8
4f5da8
From: Li Qiang <liqiang6-s@360.cn>
4f5da8
4f5da8
When doing bitblt copy in backward mode, we should minus the
4f5da8
blt width first just like the adding in the forward mode. This
4f5da8
can avoid the oob access of the front of vga's vram.
4f5da8
4f5da8
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
4f5da8
4f5da8
{ kraxel: with backward blits (negative pitch) addr is the topmost
4f5da8
          address, so check it as-is against vram size ]
4f5da8
4f5da8
Cc: qemu-stable@nongnu.org
4f5da8
Cc: P J P <ppandit@redhat.com>
4f5da8
Cc: Laszlo Ersek <lersek@redhat.com>
4f5da8
Cc: Paolo Bonzini <pbonzini@redhat.com>
4f5da8
Cc: Wolfgang Bumiller <w.bumiller@proxmox.com>
4f5da8
Fixes: d3532a0db02296e687711b8cdc7791924efccea0 (CVE-2014-8106)
4f5da8
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
4f5da8
Message-id: 1485938101-26602-1-git-send-email-kraxel@redhat.com
4f5da8
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
4f5da8
(cherry picked from commit 62d4c6bd5263bb8413a06c80144fc678df6dfb64)
4f5da8
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
4f5da8
---
4f5da8
 hw/display/cirrus_vga.c | 7 +++----
4f5da8
 1 file changed, 3 insertions(+), 4 deletions(-)
4f5da8
4f5da8
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
4f5da8
index 6aa29a3..e0e39ef 100644
4f5da8
--- a/hw/display/cirrus_vga.c
4f5da8
+++ b/hw/display/cirrus_vga.c
4f5da8
@@ -269,10 +269,9 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s,
4f5da8
 {
4f5da8
     if (pitch < 0) {
4f5da8
         int64_t min = addr
4f5da8
-            + ((int64_t)s->cirrus_blt_height-1) * pitch;
4f5da8
-        int32_t max = addr
4f5da8
-            + s->cirrus_blt_width;
4f5da8
-        if (min < 0 || max > s->vga.vram_size) {
4f5da8
+            + ((int64_t)s->cirrus_blt_height - 1) * pitch
4f5da8
+            - s->cirrus_blt_width;
4f5da8
+        if (min < -1 || addr >= s->vga.vram_size) {
4f5da8
             return true;
4f5da8
         }
4f5da8
     } else {
4f5da8
-- 
4f5da8
1.8.3.1
4f5da8