From d2ba7ecb348d3b996fcd920cf1ca7b72722c1dfd Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 10 Feb 2016 17:17:39 +0100
Subject: [PATCH 1/2] cirrus_vga: fix off-by-one in blit_region_is_unsafe
The "max" value is being compared with >=, but addr + width points to
the first byte that will _not_ be copied. Laszlo suggested using a
"greater than" comparison, instead of subtracting one like it is
already done above for the height, so that max remains always positive.
The mistake is "safe"---it will reject some blits, but will never cause
out-of-bounds writes.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1455121059-18280-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
hw/display/cirrus_vga.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index b6ce1c8bc7..57b91a77ca 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -276,14 +276,14 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s,
+ ((int64_t)s->cirrus_blt_height-1) * pitch;
int32_t max = addr
+ s->cirrus_blt_width;
- if (min < 0 || max >= s->vga.vram_size) {
+ if (min < 0 || max > s->vga.vram_size) {
return true;
}
} else {
int64_t max = addr
+ ((int64_t)s->cirrus_blt_height-1) * pitch
+ s->cirrus_blt_width;
- if (max >= s->vga.vram_size) {
+ if (max > s->vga.vram_size) {
return true;
}
}
From 05fa1c742fd6f66978b989ded0dd981ef11c4a0c Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Tue, 20 Oct 2015 09:57:30 +0200
Subject: [PATCH 2/2] qxl: lock current_async update in qxl_soft_reset
This should fix a defect report from Coverity.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/display/qxl.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index a423deecea..919dc5cd36 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -1156,7 +1156,9 @@ static void qxl_soft_reset(PCIQXLDevice *d)
trace_qxl_soft_reset(d->id);
qxl_check_state(d);
qxl_clear_guest_bug(d);
+ qemu_mutex_lock(&d->async_lock);
d->current_async = QXL_UNDEFINED_IO;
+ qemu_mutex_unlock(&d->async_lock);
if (d->id == 0) {
qxl_enter_vga_mode(d);